Now updated for CSW19. New words, if any, and new inflections of existing words, are shown in red.

abacus |
(Lat.) a counting device using beads. |

acalculia |
an inability to do simple mathematical calculations. |

addable |
capable of being added. |

addend |
an amount to be added. |

addendum |
(Lat.) something to be added. |

addible |
capable of being added. |

additory |
tending to add; making some addition. |

ae |
(Scots) one. No -S. |

algorism |
(Arabic) the art of calculating, esp in Arabic numeration. |

algorismic |
relating to algorism. |

aliquant |
(Lat.) of a number that divides into another with a remainder. |

aliquot |
(Lat.) a number that divides into another without leaving a remainder. |

alligation |
the calculation of values or properties of a mixture. |

antiderivative |
an indefinite integral. |

antilog |
an antilogarithm. |

antilogarithm |
a number of which a given number is the logarithm. |

antilogarithmic |
of or like an antilogarithm, a number of which a given number is the logarithm. |

augend |
(Ger.) a number to which another number is added. |

bajillion |
an unspecified but extremely large number. |

bazillion |
an indefinitely large number. |

bifold |
twofold; double; (noun) a two-piece door. |

billion |
a thousand million. |

billionth |
the ordinal of billion; (noun) a thousand millionth part. |

binal |
twofold, double. |

binarism |
the state of being binary. |

binary |
composed of two things; (noun) a combination of two things. |

binomial |
containing the sum or difference of two terms (noun) a binomial expression |

binomially |
(Adv.) BINOMIAL, relating to an expression which contains the sum or difference of two terms. |

biquadrate |
the fourth power. |

biquadratic |
a quantity twice squared, or raised to the fourth power. |

bivariant |
involving two variables; (noun) an expression involving two variables. |

bivariate |
involving or depending on two variables; (noun) a formula involving two variables. |

calculable |
that can be calculated. |

calculably |
(Adv.) CALCULABLE, that can be calculated. |

calculate |
to count or reckon. |

calculatedly |
(Adv.) CALCULATED. |

calculatingly |
(Adv.) CALCULATING. |

calculation |
the process or an act of calculating. |

calculational |
relating to calculation. |

calculative |
relating to calculation. |

calculator |
one that calculates. |

centage |
rate by the hundred. |

centesimal |
counting or counted by hundreds or hundredths. |

centesimally |
(Adv.) CENTESIMAL, counting or counted by hundreds or hundredths. |

centillion |
in UK and Germany, the hundredth power of a million, ie 1 followed by 600 zeros; in N. America and France, the hundred-and-first power of a thousand, ie 1 followed by 303 zeros. |

centillionth |
the ordinal of centillion. |

centuple |
hundredfold; (verb) to increase a hundredfold. |

centurial |
of or pertaining to a century. |

cinq |
(Fr.) the number five. |

coefficient |
any of the factors of a product considered in relation to a specific factor. |

cofactor |
a factor which occurs along with other factors in multiplication. |

colog |
(Short for) cologarithm, the logarithm of the reciprocal of a number. |

cologarithm |
the logarithm of the reciprocal of a number. |

compt |
(Obs.) to count. |

comptable |
(Obs.) countable. |

comptible |
(Obs.) countable. |

computation |
the act or action of computing. |

computational |
relating to computation. |

computationally |
(Adv.) COMPUTATIONAL, relating to computation. |

computative |
of or relating to computation. |

connumerate |
to count together. |

connumeration |
the act of connumerating. |

count |
the act of numbering; (verb) to list or mention the units of one by one to ascertain the total. |

countable |
that can be counted. |

countably |
(Adv.) COUNTABLE, that can be counted. |

crore |
(Hindi) an Indian unit of counting, ten million. |

cyclotomic |
a mathematical term relating to a polynomial. |

decad |
(Obs.) a group of ten, a decade. |

decadal |
pertaining to ten; consisting of tens. |

decennoval |
(Obs.) relating to the number nineteen. |

decillion |
the eleventh power of a thousand. |

decillionth |
one part in a decillion. |

decimal |
relating to a tenth part (noun) a fraction whose denominator is some power of ten |

decimalisation |
conversion (as of a currency) to a decimal system. |

decimalise |
to convert to a decimal system. |

decimalist |
one who advocates a decimal system. |

decimalize |
to convert to a decimal system, esp the metric system. |

decimally |
(Adv.) DECIMAL, relating to a tenth part. |

decuple |
tenfold; (verb) to make tenfold. |

denary |
having ten as a base; (noun) the number ten, a group of ten. |

denominator |
the divisor of a fraction. |

diagonalisable |
a mathematical term relating to a property of matrices. |

diagonalise |
to put (a matrix) in a form with all the nonzero elements along the diagonal from upper left to lower right. |

diagonalizable |
a mathematical term relating to a property of matrices. |

diagonalize |
to put (a matrix) in a form with all the nonzero elements along the diagonal from upper left to lower right. |

digital |
relating to digits (noun) a piano key |

digitally |
(Adv.) DIGITAL, relating to digits. |

discriminant |
a mathematical expression providing a criterion for the behavior of another more complicated expression. |

dividend |
a portion or share of anything divided, esp the share that falls to each party. |

dividendless |
without a dividend. |

divisible |
that can be divided. |

divisibly |
(Adv.) DIVISIBLE, that can be divided. |

dozenth |
the ordinal of dozen; (noun) a twelfth. |

duad |
a pair. |

dualise |
to make twofold. |

dualize |
to make twofold. |

duo |
two people considered a pair for a specific reason. |

duodecillion |
ten to the power of 39. |

duodecimal |
of or relating to the number twelve. |

duodecimally |
(Adv.) DUODECIMAL, of or relating to the number twelve. |

duodecimals |
a method of multiplying together quantities given in feet and inches, etc., without reducing them to one denomination; also called cross-multiplication. |

duodenary |
relating to the number twelve. |

duple |
having two parts or elements. |

duplex |
double; twofold; (verb) to make duple. |

duplexity |
the state of being duplex, double. |

dyad |
two units treated as one; a couple; a pair. |

dyadic |
pertaining to the number two; of two parts or elements (noun) a sum of mathematical dyads |

dyadically |
(Adv.) DYADIC, pertaining to the number two. |

eight |
the cardinal number one above seven (adj.) of the number eight. |

eighteen |
a number, ten and eight (adj.) of the number eighteen. |

eighteenth |
number eighteen in sequence; (noun) an eighteenth part. |

eighteenthly |
(Adv.) EIGHTEENTH, number eighteen in sequence. |

eightfold |
multiplied by eight; (adv.) eight times over. |

eightfoot |
measuring eight feet. |

eighth |
number eight in sequence (noun) one of eight equal parts |

eighthly |
(Adv.) EIGHTH, number eight in sequence. |

eightieth |
number eighty in sequence; (noun) one of eighty equal parts. |

eightscore |
eight times twenty. |

eightsome |
a group of eight. |

eighty |
a number, eight times ten (adj.) of the number eighty. |

eleven |
a number, ten and one. |

eleventh |
eleventh in sequence (noun) one of eleven equal parts |

eleventhly |
(Adv.) ELEVENTH, number eleven in sequence. |

ennead |
(Greek) a group of nine. |

enneadic |
relating to an ennead, a set of nine. |

enumerable |
that can be counted. |

enumerate |
to count. |

enumeration |
the act of enumerating. |

enumerative |
serving to enumerate. |

enumerator |
one that enumerates. |

equation |
the act of equating. |

equational |
relating to an equation. |

equationally |
(Adv.) EQUATIONAL, relating to an equation. |

equimultiple |
a number multiplied by the same number as another. |

exponential |
of or relating to an exponent (noun) an exponential function |

exponentially |
(Adv.) EXPONENTIAL, of or relating to an exponent. |

exponentiation |
the mathematical operation of raising a quantity to a power. |

extremum |
(Lat.) a maximum or minimum of a mathematical function. |

faciend |
(Lat.) the multiplicand. |

factor |
one of two or more quantities which, when multiplied together, result in the given quantity; (verb) to express as a product of two or more quantities. |

factorable |
that can be factored. |

factorial |
relating to a factor (noun) the product of a series of factors; spec. the product of an integer and all lower integers |

factorially |
(Adv.) FACTORIAL. |

factorisation |
the operation of resolving a quantity into factors. |

factorise |
to reduce a number to its prime factors. |

factorization |
the operation of resolving a quantity into factors. |

factorize |
to reduce a number to its prime factors. |

fifteen |
a number, five and ten (adj.) of the number fourteen. |

fifteenth |
number fifteen in sequence (noun) one of fifteen equal parts |

fifteenthly |
(Adv.) FIFTEENTH, number fifteen in sequence. |

fifth |
number five in sequence (noun) one of five equal parts |

fifthly |
(Adv.) FIFTH, number five in sequence. |

fiftieth |
number fifty in sequence; (noun) one of fifty equal parts. |

fifty |
a number, five times ten (adj.) of the number fifty. |

fiftyfold |
multiplied by fifty. |

figurework |
counting or calculation using numbers. |

finiteness |
the state of being finite. |

finitude |
the condition or state of being finite. |

first |
preceding all others (noun) something that precedes all others |

firstly |
(Adv.) FIRST, preceding all others. |

five |
a number. |

fivefold |
multiplied by five; (adv.) five times over. |

fluent |
flowing (noun) the variable quantity in fluxions |

fortieth |
number forty in sequence; (noun) one of forty equal parts. |

forty |
a number, four times ten (adj.) of the number forty. |

fortyfold |
multiplied by forty. |

four |
the cardinal number next above three. |

fourfold |
multiplied by four; (adv.) four times over. |

fourfoldness |
the state of being fourfold. |

fourscore |
(Arch.) four twenties, eighty. |

fourscorth |
(Obs.) eightieth. |

foursome |
a group of four. |

fourteen |
four and ten (adj.) of the number fourteen. |

fourteenth |
number fourteen in sequence; (noun) a fourteenth part. |

fourth |
number four in sequence (noun) one of four equal parts |

fourthly |
(Adv.) FOURTH, number four in sequence. |

fractionlet |
a small fraction. |

gazillion |
an indefinitely large number. |

ghubar |
as in ghubar numeral, any of a set of numerals forming the stage between ancient Hindu numerals and present-day Arabic numerals. |

gillion |
in Britain, a thousand millions, equal to an American billion. |

gobar |
as in gobar numeral, any of a set of numerals forming the stage between ancient Hindu numerals and present-day Arabic numerals. |

googol |
the figure 1 followed by 100 zeroes (10 raised to the hundredth power). |

googolplex |
the figure 1 followed by a googol of zeroes (10 raised to the googol power). |

grillion |
a large indefinite number. |

halfness |
the quality of being half. |

hantle |
(Scots) a lot. |

hebdomad |
a set of seven; a week. |

heptad |
a group of seven. |

hexad |
(Greek) a group of six. |

hexade |
a group of six. |

hexadecimal |
(Relating to) a number system with a base of 16. |

hexadic |
relating to a hexad, a group of six. |

hundred |
a number, ten times ten (adj.) of the number hundred. |

hundredfold |
multiplied by one hundred; (adv.) a hundred times over; (noun) a multiplication by one hundred. |

hundredth |
the ordinal of hundred; (noun) a hundredth part. |

idempotency |
the state of being idempotent. |

idempotent |
relating to a quantity which does not change when squared; (noun) a quantity that does not change when squared. |

imaginarily |
(Adv.) IMAGINARY, imagined. |

imaginary |
imagined (noun) an imaginary quantity or expression |

indivisible |
that cannot be divided (noun) an indefinitely small quantity |

inequation |
an inequality. |

infimum |
(Lat.) the greatest lower bound. |

infinite |
without limit (noun) something that has no limits |

infinitely |
(Adv.) INFINITE, without limits. |

infinitesimal |
taking on values arbitrarily close to but greater than zero (noun) an infinitesimal number |

infinitesimally |
(Adv.) INFINITESIMAL, taking on values arbitrarily close to but greater than zero. |

infinity |
the state of having no limits. |

innumeracy |
the state of being innumerate. |

innumerate |
marked by an ignorance of mathematics and the scientific approach; (noun) one who is innumerate. |

innumerous |
(Arch.) innumerable. |

integer |
a whole number. |

integral |
whole (noun) a type of mathematical function |

integrally |
(Adv.) INTEGRAL, whole. |

invariant |
not varying; (noun) an invariant quantity. |

jillion |
an indefinite but extremely large number. |

jillionth |
the ordinal of jillion. No -S. |

kazillion |
an indefinitely large number. |

known |
a mathematical quantity whose value is given. |

lakh |
(Hindi) a unit of counting, one hundred thousand. |

lashings |
(Coll.) an abundance. |

lashins |
(Coll.) an abundance. |

logarithm |
a mathematical operation used esp before electronic computing, to simplify multiplication and division. |

logarithmic |
of or like a logarithm. |

logarithmical |
of or like a logarithm. |

logarithmically |
(Adv.) LOGARITHMICAL, of or like a logarithm. |

loglog |
the logarithm of a logarithm. |

lolog |
the logarithm of a logarithm. |

mantissa |
(Lat.) the decimal part of a logarithm. |

manyfold |
many in number. |

maximum |
(Lat.) greatest (noun) the largest amount |

maximumly |
(Adv.) MAXIMUM, greatest. |

mille |
(Fr.) a thousand. |

millenary |
a group of a thousand. |

millesimal |
thousandth; consisting of thousandth parts (noun) a thousandth part |

millesimally |
(Adv.) MILLESIMAL, relating to a thousandth part. |

milliard |
(Fr.) a thousand million. |

million |
a thousand thousand. |

millionary |
relating to or consisting of millions. |

millionfold |
multiplied by a million; (adv.) a million times over. |

millionth |
the ordinal of million; (noun) a millionth part of. |

minuend |
a number from which another is to be subtracted. |

minus |
a negative quantity. |

modulo |
(Lat.) with respect to a modulus of (a given value). |

modulus |
(Lat.) a number leaving the same remainder when divided into two others. |

monad |
the number one; a unit; a single-celled organism. |

monadal |
relating to a monad. |

monadic |
relating to a monad. |

monadical |
of, pertaining to, or like, a monad, in any of its senses. |

monadically |
(Adv.) MONADICAL, of, pertaining to a monad. |

monas |
the number one; a unit; a single-celled organism. |

monic |
denoting a type of polynomial. |

monie |
(Scots) many. |

monomial |
consisting of one term only; (noun) a monomial expression. |

mony |
(Scots) many. |

much |
plentiful (noun) a great deal |

muchly |
(Arch.) much. |

multeity |
multiplicity. |

multibillion |
comprising many billions. |

multifold |
many times doubled; manifold. |

multimillion |
comprising many millions. |

multinomial |
a mathematical expression that consists of the sum of several terms. |

multiplex |
manifold; multiple; (verb) to incorporate into a multiplex signal or system. |

multiplicand |
a number or amount to be multiplied. |

multiplicator |
a multiplier. |

multitrillion |
a number or amount equal to several trillion. |

multitudinous |
existing in a great multitude. |

multitudinously |
(Adv.) MULTITUDINOUS, existing in a great multitude. |

myriad |
(Greek) ten thousand. |

myriadfold |
multiplied by a myriad; (adv.) a myriad times over; (noun) a myriad times. |

myriadth |
the ordinal from myriad; (noun) one of a myriad equal parts. |

nilpotent |
a quantity which equals zero when multiplied by itself. |

nine |
the cardinal number above eight (adj.) of the number nine. |

ninefold |
multiplied by nine; (adv.) nine times over. |

ninescore |
nine time twenty; (noun) nine times twenty. |

nineteen |
ten and nine (adj.) of the number nineteen. |

nineteenth |
number nineteen in sequence (noun) a nineteenth part |

nineteenthly |
(Adv.) NINETEENTH. |

ninetieth |
the ordinal of ninety; (noun) one of ninety equal parts. |

ninety |
a number, nine times ten (adj.) of the number ninety. |

ninth |
in the ninth place (noun) one of nine equal parts |

ninthly |
(Adv.) NINTH, in ninth place. |

nonary |
of a mathematical system, based on nine; (noun) a group of nine. |

nonbinary |
not binary. |

nonillion |
the 10th power of a thousand. |

nonillionth |
the ordinal of nonillion. |

nonuple |
a set of nine. |

nonvanishing |
a quantity that is nonzero everywhere is said to be nonvanishing. For instance, the values of x squared + 1 are nonvanishing for real x, while those of x squared are not (since x vanishes at 0). |

nonzero |
not zero. |

novemdecillion |
ten to the 114th power. |

novenary |
a set of nine. |

nth |
an ordinal implying a large indefinite number. |

number |
that by which single things are counted or reckoned; (verb) to count. |

numberable |
that can be numbered. |

numberless |
without number, countless. |

numberlessly |
(Adv.) NUMBERLESS, without number, countless. |

numerable |
that can be numbered. |

numerably |
(Adv.) NUMERABLE, that can be numbered. |

numeral |
according to number (noun) a symbol that expresses a number |

numerally |
(Adv.) NUMERAL, according to number. |

numerary |
belonging to a certain number; counting as one of a collection or body. |

numerate |
to compute, calculate. |

numeration |
the act of counting or numbering. |

numerative |
relating to numeration. |

numerator |
one who numbers. |

numeric |
relating to number (noun) a numeral |

numerical |
relating to number. |

numerically |
(Adv.) NUMERICAL, relating to number. |

numerosity |
the state of being numerous. |

octad |
a set of eight things. |

octadic |
relating to an octad, a set of eight. |

octal |
relating to or based on the number eight; (noun) a numbering system using a base of 8. |

octillion |
the ninth power of a thousand. |

octillionth |
the ordinal of a thousand raised to the ninth power part; (noun) one of an octillion equal parts. |

octodecillion |
ten to the 108th power. |

octonary |
based on the number eight; (noun) a group of eight things. |

octuple |
eightfold (verb) to multiply by eight |

octuplex |
being eight times as great. |

octuply |
(Adv.) OCTUPLE, eightfold. |

ogdoad |
a group of eight. |

one |
single, of unit number; (noun) an individual thing or person; the number or figure 1. |

oodles |
lots of. |

oodlins |
lots of. |

operand |
a quantity on which a mathematical or logical operation is (to be) performed. |

outadd |
to surpass in adding. |

pentad |
a set of five. |

pentadic |
in a set of five. |

pentalogy |
the state of being in five parts. |

percent |
one part in a hundred. |

percentage |
a part of a whole expressed in hundredths. |

percental |
relating to percentages. |

permillage |
reckoning by the thousand. |

polynomialism |
the state of being polynomial. |

primeness |
the state of being first. |

pseudorandom |
being or involving entities (as numbers) that are selected by a definite computational process but that satisfy one or more standard tests for statistical randomness. |

pseudoscalar |
a variable quantity that has magnitude but not direction and is an odd function of the coordinates. |

pseudovector |
a variable quantity, such as angular momentum, that has magnitude and orientation with respect to an axis. |

quadratic |
involving the square but no higher power (noun) a quadratic equation |

quadratical |
involving the square but no higher power, as a quadratic equation. |

quadratically |
(Adv.) QUADRATICAL, involving the square but no higher power, as a quadratic equation. |

quadrillion |
a thousand raised to the fifth power. |

quadrillionth |
the ordinal of quadrillion; (noun) one of a quadrillion equal parts. |

quadrinomial |
an expression of four terms. |

quadruple |
fourfold; (noun) four times as much; (verb) to increase fourfold. |

quaternary |
a set of four. |

quaternate |
in sets of four. |

quaternion |
a set or group of four; the operation of changing one vector into another, or the quotient of two vectors. |

quaternity |
fourness; any group of four things. |

quinary |
fivefold; (noun) a set of five. |

quindecaplet |
a group of fifteen. |

quindecillion |
ten to the power of 48, or in Britain ten to the power of 90. |

quintic |
an equation of the fifth degree. |

quintillion |
a thousand raised to the sixth power. |

quintillionth |
the ordinal of quintillion; (noun) a quintillionth part. |

quintuple |
fivefold (verb) to make fivefold |

quintuply |
(Adv.) QUINTUPLE, fivefold. |

quotient |
the result obtained by dividing one quantity by another. |

quotition |
a division regarded as a repeated subtraction. |

radicand |
a quantity in mathematics. |

ratio |
(Lat.) the relation of one thing to another of which the quotient is the measure. |

rational |
conforming to reason (noun) a number that can be expressed as a quotient of integers |

rationally |
(Adv.) RATIONAL, conforming to reason. |

readd |
to add again. |

reciprocal |
acting in return (noun) something in a reciprocal relationship to another |

reciprocally |
(Adv.) RECIPROCAL, acting in return. |

reciprocant |
in maths, a differential invariant. |

renormalise |
to subject to or calculate using renormalisation. |

renormalize |
to subject to or calculate using renormalization. |

repunit |
a number consisting of two or more identical integers. |

rhizic |
of the root of an equation. |

scalar |
a quantity that has magnitude, but not direction. |

scaleup |
an increase based on a fixed ratio. |

senary |
a set of six. |

septenary |
a group of seven. |

septendecillion |
ten to the power of 54. |

septet |
a set of seven persons or objects; as, a septet of singers. |

septette |
a set of seven persons or objects; as, a septette of singers. |

septillion |
a thousand raised to the eighth power (10 to the 24). |

septillionth |
the ordinal of septillion. |

septimal |
relating to or based on the number seven. |

septuple |
sevenfold; (verb) to multiply by seven. |

seven |
a number. |

sevenfold |
multiplied by seven; (adv.) seven times over. |

seventeen |
a number, ten and seven (adj.) of the number seventeen. |

seventeenth |
number seventeen in sequence (noun) a seventeenth part |

seventeenthly |
(Adv.) SEVENTEENTH. |

seventh |
seventh in sequence (noun) one of seven equal parts |

seventhly |
(Adv.) SEVENTH, seventh in sequence. |

seventieth |
a seventieth part of. |

seventy |
a number, seven times ten (adj.) of the number seventy. |

sexagenary |
of, containing, based on, sixty. |

sexagesimal |
relating to, or based on, sixty (noun) a sexagesimal fraction |

sexagesimally |
(Adv.) SEXAGESIMAL, based on 60. |

sexdecillion |
ten to the power of 51. |

sextillion |
a thousand raised to the seventh power (10 to the 21). |

sextillionth |
the ordinal of a sextillion, a thousand raised to the seventh power. |

sextuple |
sixfold (verb) to multiply sixfold |

shwanpan |
(Chinese) a Chinese abacus. |

six |
the next whole number after five (adj.) of the number six. |

sixfold |
multiplied by six; (adv.) six times over. |

sixscore |
six times twenty. |

sixteen |
a number, ten and six (adj.) of the number sixteen. |

sixteenth |
number sixteen in sequence (noun) the sixteenth part of something |

sixteenthly |
(Adv.) SIXTEENTH. |

sixth |
number six in sequence (noun) one of six equal parts |

sixthly |
(Adv.) SIXTH, number six in sequence. |

sixtieth |
number sixty in sequence; (noun) one of sixty equal parts. |

sixty |
a number, six times ten (adj.) of the number sixty. |

sixtyfold |
multiplied by sixty. |

soroban |
(Japanese) a Japanese abacus. |

sphenic |
wedge-shaped; (maths) having three different prime numbers as its factors. |

spinor |
a type of mathematical vector. |

squillion |
an indefinitely large number. |

subduple |
in the ratio of one to two. |

subfactorial |
something below a factorial. |

submatrix |
part of a matrix. |

submultiple |
dividing into another exactly; (noun) a quantity that divides into another exactly. |

subseries |
a subdivision of a series. |

subtotal |
partially total (verb) to form an interim total |

subtotally |
(Adv.) SUBTOTAL, partially total. |

subtract |
to take away. |

subtraction |
the act of subtracting. |

subtrahend |
the sum or number to be subtracted, or taken from another. |

subtriplicate |
expressed by the cube root. |

subzero |
registering less than zero. |

summable |
that can be summed. |

summand |
an addend, a number to be added in a sum. |

summate |
to add together. |

summation |
the act of summing. |

summational |
relating to summation, the act of summing. |

summative |
relating to summation, the act of summing. |

surd |
lacking sense, irrational; (noun) a sum containing irrational roots; a voiceless sound in speech. |

swanpan |
(Chinese) a Chinese abacus. |

tally |
a count; (verb) to count up, reckon. |

ten |
the next whole number after nine (adj.) of the number ten. |

tenfold |
multiplied by ten; (adv.) ten times over; (noun) a multiplication by ten. |

tenth |
number ten in sequence (noun) one of ten equal parts |

tenthly |
(Adv.) TENTH, ten in sequence. |

ternal |
threefold. |

ternary |
in threes; (noun, obs.) a set or group of three. |

tertius |
(Lat.) third; (noun) a third person. |

tetrad |
the number four; a collection of four things. |

tetradic |
of or pertaining to a tetrad; as, a carbon is a tetradic element. |

third |
number three in sequence (noun) one of three equal parts; (verb) to divide by three |

thirding |
a third part. |

thirdly |
(Adv.) THIRD, number three in sequence. |

thirteen |
a number, three and ten (adj.) of the number thirteen. |

thirteenth |
number thirteen in sequence (noun) a thirteenth part of |

thirteenthly |
(Adv.) THIRTEENTH. |

thirtieth |
the ordinal of thirty; (noun) one of thirty equal parts. |

thirty |
a number, three times ten (adj.) of the number thirty. |

thirtyfold |
multiplied by thirty; (adv.) thirty times over. |

thousand |
a number, ten hundreds (adj.) of the number thousand. |

thousandfold |
multiplied by a thousand; (adv.) a thousand times over; (noun) a thousand times as much. |

thousandth |
number thousand in sequence; (noun) a thousandth part of. |

thrave |
(Scots) a collective noun for a number of sheaves of corn, two stooks of twelves sheaves each. |

threave |
(Scots) a collective noun for a number of sheaves of corn, two stooks of twelves sheaves each. |

three |
a number, three ones (adj.) of the number three. |

threefold |
multiplied by three; (adv.) three times over. |

threeness |
the quality of being three. |

threescore |
three times twenty. |

threesome |
a set of three. |

thretty |
(Dial.) thirty. |

thrice |
three times. |

totalise |
to find the sum of; to bring to a total. |

totalize |
to find the sum of; to bring to a total. |

totient |
the number of totitives of a number, i.e. numbers less than and prime to it. |

totitive |
a number less than and prime to another. |

transcendental |
transcending; (noun) a transcendental number. |

tredecillion |
ten to the power of 42. |

triad |
a set of three. |

triadism |
a triadic method, system, principle, or arrangement. |

triality |
three united; the state of being three. |

trifold |
threefold. |

trillion |
a number. |

trillionth |
number trillion in sequence; (noun) a trillionth part. |

trinal |
threefold. |

trinary |
in a group of three. |

trinomial |
of three terms joined by + or - (noun) a trinomial expression |

trinomially |
(Adv.) TRINOMIAL, relating to a mathematical expression of three terms joined by + or -. |

triple |
threefold; (verb) to make three times as great. |

triplicate |
to make triple or threefold. |

triplicity |
the state of being triple. |

trois |
(Fr.) three. |

twa |
(Scots) two. |

twae |
(Scots) two. |

twafald |
(Scots) twofold. |

twain |
(Arch.) two. |

twal |
(Scots) twelve. |

twasome |
(Scots) a twosome. |

tway |
(Scots) a form of twain or twa. |

twelfth |
twelfth in sequence (noun) the number twelve in a series |

twelfthly |
(Adv.) TWELFTH, twelfth in sequence. |

twelve |
a number, two and ten (adj.) of the number twelve. |

twelvefold |
twelve in number. |

twentieth |
number twenty in sequence; (noun) one of twenty equal parts. |

twenty |
a number. |

twentyfold |
multiplied by a twenty; (adv.) twenty times over; (noun) twenty times as much. |

twentyish |
about twenty esp in age. |

twice |
two times. |

twifold |
twofold. |

two |
the next whole number after one (adj.) of the number two. |

twoer |
(Coll.) anything that counts as two or scores two. |

twofold |
double; (adv.) twice over; (noun) an amount twice as great as a given unit. |

twoness |
the state of being two. |

twosome |
a pair. |

twyfold |
twofold. |

umpteen |
denoting an indefinitely large number. No -S. |

umpteenth |
the ordinal of umpteen; (noun) an indefinitely large number in a sequence. |

umptieth |
denoting an indefinitely large number in a sequence. |

umpty |
designating an indefinitely large number > UMPTIEST. |

umteenth |
denoting an indefinitely large number in a sequence. |

unary |
consisting of a single element. |

uncountable |
not countable. |

undecillion |
a large number - a one followed by either 36 or 66 zeroes. |

undecimal |
based on the number eleven. |

unit |
a specific quantity used as a standard of measurement. |

unital |
relating to a unit. |

unitarily |
(Adv.) UNITARY, of the nature of a unit. |

unitary |
of the nature of a unit; having the separate existence or individual character of a unit. |

unity |
the state of being one single entity. |

vicenary |
based on the number twenty. |

vicesimal |
based on the number twenty. |

vigesimal |
based on the number twenty. |

vigintillion |
ten to the power of 63. |

wheen |
(Scots) a few, a good many. |

zero |
(Fr.) the sign for nothing (verb) to set at or adjust to zero |

zeroth |
being numbered zero in a series. |

zillion |
an extremely large but unspecified number, many millions. |

zillionth |
the ordinal of zillion; (noun) a zillionth part of something. |

zonoid |
like a zone; (noun) a finite vector sum of line segments. |