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American Heritage Dictionary - Cite This Source - Share This

ver·tex       (vûr'těks')  Pronunciation Key  n.   pl. ver·ti·ces (-tĭ-sēz') also ver·tex·es The highest point; the apex or summit: the vertex of a mountain. Anatomy The highest point of the skull. The top of the head. The point at which the sides of an angle intersect. The point on a triangle or pyramid opposite to and farthest away from its base. A point on a polyhedron common to three or more sides. Astronomy The highest point reached in the apparent motion of a celestial body. Mathematics The point at which the sides of an angle intersect. The point on a triangle or pyramid opposite to and farthest away from its base. A point on a polyhedron common to three or more sides. [Latin, whirlpool, crown of the head (where the hair forms a whorl), vertex, from vertere, to turn; see wer-2 in Indo-European roots.]

Online Etymology Dictionary - Cite This Source - Share This
vertex 

WordNet - Cite This Source - Share This

vertex
noun
1.	the point of intersection of lines or the point opposite the base of a figure
2.	the highest point (of something); "at the peak of the pyramid"

The American Heritage Science Dictionary - Cite This Source - Share This

vertex       (vûr'těks')  Pronunciation Key  Plural vertices (vûr'tĭ-sēz') or vertexes The point at which the sides of an angle intersect. The point of a triangle, cone, or pyramid that is opposite to and farthest away from its base. A point of a polyhedron at which three or more of the edges intersect.

American Heritage Stedman's Medical Dictionary - Cite This Source - Share This

vertex ver·tex (vûr'těks')
n. pl. ver·tex·es or ver·ti·ces (-tĭ-sēz')

1. The highest point; the apex.
2. The topmost point of the vault of the skull; the crown of the head.
3. The portion of the fetal head bounded by the planes of the trachelobregmatic and biparietal diameters, with the posterior fontanel at the apex.

Merriam-Webster's Medical Dictionary - Cite This Source - Share This
Main Entry: ver·tex
Pronunciation: 'v&r-"teks
Function: noun
Inflected Form: plural ver·ti·ces /'v&rt-&-"sEz/ also ver·tex·es
1 : the top of the head
2 : the highest point of the skull

Webster's Revised Unabridged Dictionary - Cite This Source - Share This

Vertex

Ver"tex\, n.; pl. Vertexes, L. Vertices. [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. Specifically: (a) (Anat.) The top, or crown, of the head. (b) (Anat.) The zenith, or the point of the heavens directly overhead. (c) (Math.) The point in any figure opposite to, and farthest from, the base; the terminating point of some particular line or lines in a figure or a curve; the top, or the point opposite the base.

Note: 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.

Vertex of a curve (Math.), the point in which the axis of the curve intersects it.

Vertex of an angle (Math.), the point in which the sides of the angle meet.

Vertex of a solid, or of a surface of revolution (Math.), the point in which the axis pierces the surface.

On-line Medical Dictionary - Cite This Source - Share This

vertex

vertex: in CancerWEB's On-line Medical Dictionary