Vertex /(?)/

Ver·tex

Vertex

n.

pl. Vertexes, Vertices

  1. A turning point; the principal or highest point; top; summit; crown; apex.
  2. The top, or crown, of the head. (Anat.)
  3. The zenith, or the point of the heavens directly overhead. (Astron.)
  4. 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. (Math.)

Phrases & Compounds
Vertex of a curve
the point in which the axis of the curve intersects it.
Vertex of an angle
the point in which the sides of the angle meet.
Vertex of a solid
the point in which the axis pierces the surface.