Now updated for CSW19. New words, if any, and new inflections of existing words, are shown in red.
| agonic | making no angle. |
| antiparallel | making with a transverse line an internal angle equal to the external angle made by another line; (noun) an antiparallel line. |
| apothem | (Greek) the perpendicular from the centre of a regular polygon to any of its sides. |
| arc | a part of the circumference of a circle or other curve; (verb) to form an arc. |
| arccosine | a mathematical function. |
| arcmin | 1/60 of a degree of angle. |
| arcminute | a unit of angular measurement, one sixtieth of a degree. |
| arcsec | a unit of angle measurement, 1/3600 of a degree. |
| arcsine | a geometrical ratio. |
| arctangent | a geometrical ratio. |
| asymmetry | lack of symmetry. |
| axis | (Lat.) the imaginary straight line about which a body such as the earth rotates the white-spotted deer of India |
| axised | having an axis. |
| bilinear | of or involving two lines. |
| bisector | one who, or that which, bisects; esp in geometry a straight line which bisects an angle. |
| brachypinakoid | a pinakoid or prism parallel to the brachydiagonal. |
| brachyprism | a prism parallel to the brachydiagonal. |
| catenoid | the surface generated by rotating a catenary about its axis. |
| cathetus | (Greek) a straight line perpendicular to another straight line or surface. |
| chiliagon | (Greek) a plane figure of a thousand angles and sides. |
| chiliahedron | (Greek) a one-thousand sided solid figure. |
| circumcenter | the point at which the perpendicular bisectors of the sides of a triangle intersect and which is equidistant from the three vertices. |
| circumcentre | the point at which the perpendicular bisectors of the sides of a triangle intersect and which is equidistant from the three vertices. |
| circumcircle | a circle which passes through all the vertices of a polygon, such as a triangle. |
| coaxial | having the same axis. |
| coaxially | (Adv.) COAXIAL, having the same axis. |
| cofunction | a kind of trigonometric function. |
| colinear | in the same straight line. |
| colinearity | the state of being colinear. |
| collimation | the act of making parallel. |
| collinear | in the same straight line. |
| collinearly | (Adv.) COLLINEAR, in the same straight line. |
| conic | cone-shaped, conical (noun) a conic section |
| conoidic | nearly, but not exactly, conical. |
| conoidical | nearly, but not exactly, conical. |
| coplanar | on the same plane. |
| coplanarity | the state of being coplanar. |
| cosec | (Short for) cosecant, the secant of the complement of an arc or angle. |
| cosecant | the secant of the complement of an arc or angle. |
| cosech | (Short for) hyberbolic cosecant. |
| cosine | a trigonometric function of an angle. |
| cotan | (Short for) cotangent, the tangent of the complement of an arc or angle. |
| cotangent | the tangent of the complement of an arc or angle. |
| coth | (Short for) hyperbolic cotangent. |
| coversed | as in coversed sine, an obsolete function in trigonometry. |
| coversine | a function in trigonometry. |
| crunodal | relating to a crunode, the point at which a curve crosses itself. |
| crunode | the point at which a curve crosses itself. |
| cubage | the process of finding the cubic content of a body. |
| cubature | the determination of the cubic content of a solid. |
| cubic | in the form of a cube (noun) a cubic equation |
| cubicly | (Adv.) CUBIC, in the form of a cube. |
| decagon | a plane figure with ten equal sides. |
| decagonal | of a plane figure, having ten sides. |
| decagonally | (Adv.) DECAGONAL, of a plane figure, having ten sides. |
| decahedral | having ten sides. |
| decahedron | a solid figure or body inclosed by ten plane surfaces. |
| declinator | an instrument for taking the declination or angle which a plane makes with the horizontal plane. |
| diallel | meeting and intersecting, as lines; not parallel; (noun) a scheme of cross-breeding within a select group of parents, designed to produce various hybrids with different genetic properties. |
| diameter | a straight line passing through the center of a circle and ending at the periphery. |
| diametral | pertaining to a diameter. |
| diametrally | (Adv.) DIAMETRAL, pertaining to a diameter. |
| diametric | pertaining to a diameter. |
| diametrical | pertaining to a diameter. |
| diametrically | (Adv.) DIAMETRICAL, pertaining to a diameter. |
| diedral | bounded by two planes, or two plane faces; (noun) a diedral angle. |
| digonal | of symmetry about an axis, such that a half-turn (180°) gives the same figure. |
| digoxin | a drug used to improve heart function. |
| dihedral | bounded by two planes, or two plane faces; (noun) a dihedral angle. |
| dihedron | a figure with two sides or surfaces. |
| dodecagon | a plane figure with twelve sides. |
| dodecagonal | like a dodecagon, a plane figure with twelve sides. |
| dodecahedral | relating to a dodecahedron, a twelve-sided solid figure. |
| dodecahedron | (Greek) a twelve-sided solid figure. |
| ellipsoid | a solid, all plane sections of which are ellipses or circles. |
| endecagon | an eleven-sided polygon. |
| enneagon | a polygon with nine sides. |
| enneagonal | belonging to an enneagon; having nine angles. |
| enneahedral | of or like an enneahedron, a nine-sided solid figure. |
| enneahedron | a nine-sided solid figure. |
| epicycle | a circle whose centre moves round the circumference of a larger circle. |
| epicyclic | pertaining to or having the motion of, an epicycle. |
| epicyclical | pertaining to or having the motion of, an epicycle. |
| equilateral | having all sides equal (noun) a shape with all sides equal |
| equilaterally | (Adv.) EQUILATERAL, having all sides equal. |
| escribe | to draw a circle so as to touch one side of a triangle externally; the others (produced) internally. |
| euclidean | related to Euclid, or to the geometry of Euclid. |
| euclidian | related to Euclid, or to the geometry of Euclid. |
| exsecant | a trigonometric function of an angle. |
| fractal | generated by successive subdivisions of a simpler polygon or polyhedron, according to some iterative process; (noun) a fractal shape. |
| fractality | the state of being fractal. |
| frustum | (Lat.) a slice of a solid body; the part of a cone or pyramid between the base and a parallel plane. |
| generant | a thing which generates; spec. in maths a generatrix. |
| generatrix | a line, point or figure that traces out another figure by its motion. |
| geometrically | (Adv.) GEOMETRICAL, related to geometry. |
| gon | a geometrical grade. |
| haversine | half the versed sine of an angle. |
| hemicycle | a half circle; a semicircle. |
| hendecagon | an eleven-sided polygon. |
| hendecagonal | of or like a hendecagon, an eleven-sided polygon. |
| hendecahedron | a solid figure having 11 plane faces. |
| heptagon | a seven-sided plane figure. |
| heptagonal | having seven angles or sides. |
| heptahedral | like a heptahedron. |
| heptahedron | a solid figure having several plane faces. |
| heptangular | having seven angles. |
| hexagon | a six-sided plane figure. |
| hexagonal | having six sides and six angles. |
| hexagonally | (Adv.) HEXAGONAL, having six sides and six angles. |
| hexagram | a figure of six lines, esp a stellate hexagon, aka Star of David. |
| hexahedral | in the form of a hexahedron. |
| hexahedron | a solid body of six sides or faces. |
| holohedral | having all the planes required by complete symmetry, as opposed to hemihedral. |
| holohedrism | the property of having the full number of symmetrically arranged planes crystallographically possible. |
| holohedron | a geometrical form possessing the property of holohedrism. |
| homaloid | a Euclidean space, analogous to a plane. |
| homaloidal | of the nature of a homaloid; flat; plane-shaped. |
| homoeomorphic | of two geometrical figures, such that one can be converted into the other by distortion. |
| homoeomorphism | the state of being homoeomorphic. |
| hyperboloid | a solid figure in which some of the plane sections are hyperbolas. |
| hyperboloidal | of or like a hyperboloid. |
| hypercube | a figure in a space of four or more dimensions having all its sides equal and all its angles right angles. |
| hyperplane | a figure in hyperspace corresponding to a plane in ordinary space. |
| hyperspace | an imagined space having more than three dimensions. |
| hyperspatial | relating to hyperspace, an imagined space having more than three dimensions. |
| hypotenuse | the longest side of a right-angled triangle. |
| hypothenuse | the longest side of a right-angled triangle. |
| icosahedral | of or having the form of an icosahedron. |
| icosahedron | a polyhedron having 20 faces. |
| icositetrahedra | solid figures with twenty-four plane faces. |
| incenter | the centre of an inscribed circle or sphere. |
| incentre | the centre of an inscribed circle or sphere. |
| interradial | between radii or rays. |
| interradially | (Adv.) INTERRADIAL, between radii or rays. |
| interradius | a radius midway between primary radii or perradii. |
| isogon | an equiangular polygon. |
| isoperimeter | a figure with perimeter equal to another. |
| isoperimetry | the state of being isoperimetrical. |
| isosceles | a triangle with two equal sides. |
| manifolder | one who makes manifolds. |
| nonagon | a nine-sided figure. |
| nonagonal | with nine angles. |
| nonvector | something that is not a vector. |
| obconical | conical, but having the apex downward; inversely conical. |
| octagon | an eight-sided plane figure. |
| octagonal | having eight sides and eight angles. |
| octagonally | (Adv.) OCTAGONAL, having eight sides and eight angles. |
| octahedral | having eight faces or sides. |
| octahedrally | (Adv.) OCTAHEDRAL, having eight faces or sides. |
| octahedron | (Greek) a solid bounded by eight plane faces. |
| octangle | an octagon. |
| octangular | having eight angles. |
| octant | the eighth part of circle (45°); an angle-measuring instrument with that arc. |
| octantal | relating to an octant, the eighth part of circle (45°). |
| octohedron | (Greek) a solid bounded by eight plane faces. |
| orthocenter | the point of intersection of the altitudes of a triangle. |
| orthocentre | the point of intersection of the altitudes of a triangle. |
| orthogonal | at right angles; unrelated or independent of each other. |
| orthogonality | the state of being orthogonal. |
| orthogonally | (Adv.) ORTHOGONAL, right-angled. |
| paraboloid | a surface or solid generated by the rotation of a parabola about its axis. |
| paraboloidal | of or like a paraboloid. |
| parallelogram | a quadrilateral with opposite sides parallel and equal. |
| parallelopiped | a solid figure bounded by six parallelograms, opposite pairs being identical and parallel. |
| parallelwise | in parallel fashion. |
| pentagon | a five-sided plane figure. |
| pentagonal | having five corners or angles (noun) a pentagonal shape |
| pentagonally | (Adv.) PENTAGONAL, having five corners or angles. |
| pentahedral | of or like a pentahedron, a five-sided solid figure. |
| pentahedron | a five-sided solid figure. |
| perigon | (Greek) an angle of 360 degrees. |
| perimeter | the circuit or boundary of any plane figure. |
| perpendicular | at right angles to a line or plane (noun) a perpendicular line |
| planar | relating to a plane, lying in a single plane. |
| planarity | the property of being planar, lying in a single plane. |
| planate | having a flat surface. |
| polar | relating to a pole; (noun) a term in geometry. |
| polyaxial | a shape having many axes or several axis cylinders. |
| polyaxon | having many axes or several axis cylinders; (noun) a figure with many axes. |
| polyconic | pertaining to, or based upon, many cones. |
| polygon | (Greek) a plane figure bounded by straight lines, esp more than four. |
| polyhedral | having many faces or planes. |
| polyhedric | having many faces or planes. |
| polyhedron | a body or solid contained by many sides or planes. |
| polyomino | a flat, many-sided shape made of up of identical squares placed side by side. |
| porism | (Greek) the geometric proposition that it is possible, in certain conditions, for a problem to have any number of solutions. |
| porismatic | relating to a porism, the geometric proposition that it is possible, in certain conditions, for a problem to have any number of solutions. |
| porismatical | relating to a porism, the geometric proposition that it is possible, in certain conditions, for a problem to have any number of solutions. |
| poristic | relating to a porism, the geometric proposition that it is possible, in certain conditions, for a problem to have any number of solutions. |
| poristical | relating to a porism, the geometric proposition that it is possible, in certain conditions, for a problem to have any number of solutions. |
| prism | (Greek) a solid figure of which the two ends are similar, equal, and parallel rectilineal figures, and the sides parallelograms. |
| prismoid | a body that approaches to the form of a prism. |
| prismoidal | having the form of a prismoid. |
| prismy | pertaining to a prism. |
| pyritohedral | of or like a pyritohedron, a pentagonal dodecahedron. |
| pyritohedron | a pentagonal dodecahedron. |
| quadrant | a quarter circumference of circle; an instrument for measuring altitudes. |
| quadrantal | of or pertaining to a quadrant. |
| quadrature | the finding of a square having the same area as some given curvilinear figure. |
| quadrilateral | a polygon of four sides. |
| quindecagon | a geometric figure having fifteen sides and fifteen angles. |
| rabat | (Fr.) to rotate into coincidence with another plane. |
| rabatment | rotation into coincidence with another plane. |
| rabatte | (Fr.) to rotate into coincidence with another plane. |
| rabatting | the act of rabatting. |
| radiant | shining (noun) a straight line from a point about which it is conceived to revolve |
| radiantly | (Adv.) RADIANT, shining. |
| rectangle | a four-sided plane figure with all its angles right angles, esp one with unequal adjacent sides. |
| rectilineal | moving in or forming a straight line. |
| rectilineally | (Adv.) RECTILINEAL, moving in or forming a straight line. |
| rectilinear | moving in or forming a straight line. |
| rectilinearity | the state of being rectilinear. |
| rectilinearly | (Adv.) RECTILINEAR, moving in or forming a straight line. |
| rhomb | an equilateral parallelogram. |
| rhombic | of or like a rhombus, an equilateral parallelogram. |
| rhombical | of or like a rhombus, an equilateral parallelogram. |
| rhombohedral | shaped like a rhombohedron. |
| rhombohedron | a parallelepiped whose faces are rhombuses. |
| rhomboid | a parallelogram with unequal sides. |
| rhomboidal | having, or approaching, the shape of a rhomboid. |
| rhomboides | a rhomboid. |
| rhomboideus | a rhomboid. |
| rhombus | (Lat.) an equilateral parallelogram. |
| scalene | of a triangle, having three unequal sides; (noun) the scalene muscle or scalenus. |
| scalenohedron | a hemihedral form bounded in the hexagonal system by twelve, in the tetragonal by eight, faces, each a scalene triangle. |
| sech | a hyperbolic secant. |
| sectoral | of or pertaining to a sector; as, a sectoral circle. |
| semiangle | the half of a given, or measuring, angle. |
| semicircle | the half of a circle. |
| semicircled | enclosed within a semicircle. |
| semidiameter | half the diameter, esp the angular diameter. |
| semiperimeter | half the perimeter. |
| simplex | (Lat.) a geometrical term, a figure with a minimum number of vertices. |
| simplicial | of or relating to simplexes. |
| simplicially | (Adv.) SIMPLICIAL, of or relating to simplexes. |
| sinh | a hyperbolic function of an angle. |
| sinical | of or pertaining to a sine. |
| square | having four equal sides and four right angles; rigidly conventional (noun) a shape with four equal sides and four right angles; (verb) to make square |
| squarely | (Adv.) SQUARE, having four equal sides and four right angles. |
| subparallel | almost parallel. |
| subtangent | the part of the axis contained between the ordinate and tangent drawn to the same point in a curve. |
| subtend | to be opposite to or to extend under. |
| subtense | a line subtending, or stretching across; a chord; as, the subtense of an arc. |
| symmetral | of symmetry. |
| tangent | a line that touches a curve. |
| tangental | of or pertaining to the nature of a tangent. |
| tangentally | in the direction of a tangent. |
| tangential | of or pertaining to the nature of a tangent. |
| tanh | (Short for) a hyperbolic tangent. |
| tesseract | a figure of a cube within a cube. |
| tetartohedral | having one fourth the number of planes required by complete symmetry. |
| tetartohedrally | (Adv.) TETARTOHEDRAL, having one fourth the number of planes required by complete symmetry. |
| tetartohedrism | the state of being tetartohedral, having one fourth the number of planes required by complete symmetry. |
| tetragon | a plane figure with four angles and four sides. |
| tetragonal | of or pertaining to a tetragon. |
| tetragonally | (Adv.) TETRAGONAL, of or pertaining to a tetragon. |
| tetrahedral | of a solid with four sides. |
| tetrahedrally | (Adv.) TETRAHEDRAL, of a solid with four sides. |
| tetrahedron | a polyhedron that has four faces. |
| tore | a surface described by rotation of conic section about a line. |
| toroidal | like a toroid, shaped like a doughnut or anchor-ring. |
| toroidally | (Adv.) TOROIDAL, like a toroid, shaped like a doughnut or anchor-ring. |
| tractrix | a curve such that the intercept of a tangent by a fixed straight line is constant. |
| trapezial | like a trapezium. |
| trapeziform | in the form of a trapezoid quadrilateral with no sides parallel. |
| trapezium | (Lat.) a quadrilateral with two parallel sides. |
| trapezoidal | in the form of a trapezium. |
| triangle | a polygon having three sides. |
| triangled | having a triangle. |
| trigon | a figure having three angles; a triangle. |
| trigonal | pertaining to or having three angles. |
| trigonally | (Adv.) TRIGONAL, pertaining to or having three angles. |
| trigonic | pertaining to or having three angles. |
| trigonometric | relating to trigonometry. |
| trigonometrical | relating to trigonometry. |
| trigonometry | the study of the properties of triangles and trigonometric functions and of their applications. |
| trihedral | a solid having three sides or faces; thus, a trihedral angle is a solid angle bounded by three plane angles. |
| trihedron | a figure having three sides. |
| trisoctahedron | a solid figure having 24 congruent faces and an octahedron as a base. |
| tromino | a flat, three-sided shape made up of a number of identical squares placed edge to edge. |
| twistor | a complex variable representing spacetime coordinates. |
| undecagon | a polygon having eleven sides. |
| vectorial | of or like a vector. |
| vectorially | (Adv.) VECTORIAL, of or like a vector. |
| vectorise | to make into a vector. |
| vectorize | to make into a vector. |
| versin | a versed sine. |
| versine | a versed sine. |
| vertex | (Lat.) a point, as of an angle or polygon. |