vertex
nounThe highest point; the apex or summit.
nounThe highest point of the skull.
nounThe top of the head.
nounIn astrology, the highest point reached in the apparent motion of a celestial body.
nounThe point at which the sides of an angle intersect.
nounThe point on a triangle or pyramid opposite to and farthest away from its base.
nounA point on a polyhedron common to three or more sides.
nounA point of maximal curvature on a parabola or hyperbola.