Now updated for CSW19. New words, if any, and new inflections of existing words, are shown in red.
aeon eon | the largest division of geological time, composed of several ERAS. |
aeonian eonian | lasting for aeons, eternal. |
aeonic | lasting an AEON. N.B. no EONIC*. |
age | a long but indefinite period of time; any great division of world, human, or individual history; (verb) to grow older. |
agelong | lasting for an age or very long time. |
ahemeral | not lasting a full twenty-four hours. |
allnight | of light, fuel, food etc.: provided for the whole night. |
awee | awhile. |
awhile | for a while. |
bimester | a period of two months. |
bimillenary | a span of 2,000 years; a 2,000th anniversary. |
bimillennium | a period of two thousand years > BIMILLENNIUMS or BIMILLENNIA. |
calpa kalpa | one of the Brahmanic eons, a period of 4,320,000,000 years. At the end of each calpa the world is annihilated, which is bad luck if you happen to be around at the time. |
century | one hundred years. |
chiliad | a group of 1000; a period of 1000 years, a MILLENNIUM. [Gk. kilioi, thousand]. |
chiliadal chiliadic | relating to a CHILIAD. |
chronon | a very small unit of time, defined as a) the time required for a photon to travel the diameter of an electron or b) the time between pressing one's clock in Scrabble and seeing that there was a better move you could have played. |
coeternal | equally eternal, jointly eternal. |
coeternally | (adv.) COETERNAL, equally eternal. |
day | a period of twenty four hours, or period of daylight. |
daylong | lasting all day. |
decade | a period of ten years. |
decennium | a period of ten years > DECENNIA or DECENNIUMS. |
diel | a full 24-hour day > DIELS. |
diuturnal | of long continuance; lasting. |
downtime | the period of time when e.g. a machine is out of action. |
eon | see AEON. |
eonian | see AEONIAN. |
epact | the moon's age at the beginning of the year; the excess of the calendar month or solar year over the lunar. |
ephemeral | existing only for a day, or short period; (noun) a creature, such as a mayfly, that lives for one day only. |
epoch epocha | a division of geologic time shorter than a PERIOD. |
epochal | belonging to an EPOCH; of the nature of an EPOCH. |
epochally | (adv.) EPOCHAL, belonging to an epoch. |
era | an age; a main division of geological time. |
eternal | something lasting forever. |
eternalise eternalize | to make eternal. |
eternality | the state of being eternal. |
eternally | (adv.) ETERNAL, lasting forever. |
eterne | eternal. |
eternity | duration without beginning or end. |
evanescent | fleeting, transitory. |
evanescence | the state of being EVANESCENT. |
everlasting | lasting forever; (noun) a flower (of Helichrysum, Antennaria or other genus) that may be kept for years without much change of appearance. |
everlastingness | the state of being EVERLASTING. |
evermore | for all time to come. |
eviternal | eternal. |
eviternally | (adv.) EVITERNAL, eternal. |
eyeblink | a very short instant of time. |
femtosecond | one quadrillionth part of a second. |
forever | (noun) eternity. |
forevermore | forever. |
fortnight | a period of two weeks. |
fugacious | lasting a short time, evanescent. |
fugacity fugaciousness | the state of being FUGACIOUS. |
gliffing | the time required to give a glance, an instant. N.B. there is a noun GLIFF, but no GLIFFED*. |
hebdomad | a set of seven, a period of seven days. |
henceforward | from this time on. |
hereafter | from this time on. |
hexaemeron | the (biblical) six days of creation. |
hexaemeric | relating to a HEXAEMERON. |
horal | pertaining to hour(s); hourly. |
horary | pertaining to an hour; continuing for an hour; hourly. |
hour | sixty minutes. |
hourlong | lasting an hour. |
howre | (arch.) an hour. |
instant | a very short period of time. |
interregnum | the time during which a throne is vacant between two reigns; a lapse in a continuous series. |
intraday | occurring within a single day. |
jiff jiffy | an instant. |
jour | a day, as in jour de feste. |
kalpa | see CALPA. |
laytime | the total time allowed for the loading and unloading of cargo. |
lifelong | lasting the duration of a life. |
lifespan | the length of a life. |
lifetime | the length of a life. |
longtime | enduring for a long time, e.g. my longtime friend. |
lunation | a lunar month; the interval between successive new moons. |
lustrum | a purification of the whole Roman people made in ancient times after the census every five years; by extension a period of five years, a QUINQUENNIUM > LUSTRA or LUSTRUMS. |
meantime meanwhile | (noun) a period of time while something else is going on. |
mensual | pertaining to a month; monthly. |
microsecond | one millionth of a second. |
millennium | a period of one thousand years > MILLENNIA or MILLENNIUMS. |
millisecond | a thousandth part of a second. |
minute | sixty seconds; (adj.) small > MINUTER, MINUTEST. |
mo | a moment > MOS. |
moment | a very short period of time. |
momentany | momentary. |
momentariness | the state of being momentary. |
momentary | lasting for a moment. |
momently | for a moment. |
moneth | a month. |
month | one of the twelve conventional divisions of the year, or its length. |
monthlong | lasting for a month. |
multiday | lasting for more than one day. |
multiyear | lasting many years. |
nanosecond | a billionth of a second. |
nightlong | lasting all night. |
noughties | the decade from 2000 to 2009. |
nychthemeral | of or relating to a NYCHTHEMERON or 24-hour period. |
nychthemeron | a full period of a day and night: 24 hours. |
ouk oulk | (Scots) a week. |
period | one of the main divisions of geological time; (verb) to come or bring to an end. |
permanent | remaining, or intended to remain, indefinitely; (noun) a permanent member of staff. |
permanence permanency | the fact or state of being permanent. |
permanently | (adv.) PERMANENT. |
picosecond | a millionth of a second. |
protense | an extension in time, a duration. |
quadrennium | a period of four years > QUADRENNIA or QUADRENNIUMS. |
quadriennium | a period of four years > QUADRIENNIA or QUADRIENNIUMS. |
quinquennium | a period of five years > QUINQUENNIA or QUINQUENNIUMS. |
saeculum seculum | an astronomical or geological age > SAECULUMS, SECULUMS or SECULA. |
saronic | relating to a SAROS, q.v. |
saros | a cycle of 6585.32 days in which eclipses of the sun and moon occur in same sequence and at the same intervals as in the previous such cycle. [Gk. saros, from Babylonian sharu 3600]. |
season | one of the four natural divisions of the year, spring, summer, autumn and winter; a limited period. |
second | the SI unit of time (symbol s), defined in terms of the resonance vibration of the caesium-133 atom as the interval occupied by a specific number of cycles. |
seculum | see SAECULUM. |
semester | a period of six months; especially, a term in a college or university which divides the year into two terms. [L. semestris, from sex, six + mensis, a month]. |
sempiternal | of never-ending duration, eternal. |
sennight | the space of seven nights and days, a week. [OE seofon nihta, from seofon, seven + nihta, plural of niht, night]. |
septennate | a period of seven years; as, the septennate during which the President of the French Republic holds office. |
septennium | a period of seven years > SEPTENNIA. |
sexcentenary | relating to the number 600 or a period of 600 years. |
somewhile | once; for a time. |
subepoch | a subdivision of an EPOCH. |
subperiod | part of a PERIOD. |
svedberg | a unit of time used to measure sedimentation velocity. [From Theo Svedberg, Swedish chemist]. |
tarnal | (coll.) eternal > TARNALLY. |
temporary | lasting for a time only; not permanent. |
temporariness | the state of being TEMPORARY. |
termtime | a period during which pupils are attending school. |
timeframe | a limited or restricted period of time. |
timescale | the period within which something happens or is to happen. |
towmon towmond towmont | a twelvemonth. |
transient | not lasting long; (noun) a transient thing or being. |
transientness | the state of being TRANSIENT. |
transitoriness | the state of being TRANSITORY. |
transitory | not lasting long. |
trice | a very short time; (verb) to haul and make fast. |
triduan | lasting three DAYS. |
triennium | a period of three years > TRIENNIA or TRIENNIUMS. |
trimester | a period of three months, an academic term. |
trimestrial trimestral | relating to a TRIMESTER. |
twelvemonth | a period of twelve months. |
uptime | the time during which machinery is functioning. |
week | a period of seven days. |
weeklong | lasting for a week. |
while | an indefinite period of time. |
whilere | while. |
workaday | suitable for a work day, plain and practical; (noun) a working day. |
workweek | the working week. |
year | the time taken by the earth to orbit the sun. |
yearlong | lasting a year. |
yonks | ages, a long time. N.B. no YONK*. |
zeptosecond | a 10 to the -21 part of a second. |