Word Study
vertex
CIDE DICTIONARY
vertex, n. [L. vertex, -icis, a whirl, top of the head, top, summit, from vertere to turn. See Verse, and cf. Vortex.].
A turning point; the principal or highest point; top; summit; crown; apex. [1913 Webster]
" The principal vertex of a conic section is, in the parabola, the vertex of the axis of the curve: in the ellipse, either extremity of either axis, but usually the left-hand vertex of the transverse axis; in the hyperbola, either vertex, but usually the right-hand vertex of the transverse axis." [1913 Webster]
OXFORD DICTIONARY
vertex, n. (pl. vertices or vertexes)
1 the highest point; the top or apex.
2 Geom. a each angular point of a polygon, polyhedron, etc. b a meeting-point of two lines that form an angle. c the point at which an axis meets a curve or surface.
3 Anat. the crown of the head.
1 the highest point; the top or apex.
2 Geom. a each angular point of a polygon, polyhedron, etc. b a meeting-point of two lines that form an angle. c the point at which an axis meets a curve or surface.
3 Anat. the crown of the head.
Etymology
L vertex -ticis whirlpool, crown of a head, vertex, f. vertere turn
THESAURUS
vertex
L, acme, angle, apex, apogee, bend, bifurcation, bight, brow, cant, cap, chevron, climax, cloud nine, coin, corner, crank, crest, crook, crotchet, crown, culmen, culmination, deflection, dogleg, edge, elbow, ell, extreme limit, extremity, fork, furcation, heaven, heavens, height, heights, high noon, highest pitch, highest point, hook, inflection, knee, limit, maximum, meridian, mountaintop, ne plus ultra, no place higher, nook, noon, peak, pinnacle, pitch, point, pole, quoin, ridge, roof, seventh heaven, sky, spire, summit, swerve, tip, tip-top, top, upmost, upper extremity, uppermost, utmost, veer, very top, zag, zenith, zig, zigzagROGET THESAURUS
vertex
Summit
N summit, summity, top, peak, vertex, apex, zenith, pinnacle, acme, culmination, meridian, utmost height, ne plus utra, height, pitch, maximum, climax, culminating point, crowning point, turning point, turn of the tide, fountain head, water shed, water parting, sky, pole, tip, tip top, crest, crow's nest, cap, truck, nib, end, crown, brow, head, nob, noddle, pate, capsheaf, high places, heights, topgallant mast, sky scraper, quarter deck, hurricane deck, architrave, frieze, cornice, coping stone, zoophorus, capital, epistyle, sconce, pediment, entablature, tympanum, ceiling, attic, loft, garret, house top, upper story, summit conference, summit, peak of achievement, peak of performance, peaks and troughs, peaks and valleys (in graphs), highest &c (high), top, top most, upper most, tiptop, culminating, meridian, meridional, capital, head, polar, supreme, supernal, topgallant, atop, at the top of the tree, en flute, fleur deau.For further exploring for "vertex" in Webster Dictionary Online