vertex

/ˈvər-ˌteks/

Middle English, top of the head, from Latin vertic-, vertex, vortic-, vortex whirl, whirlpool, top of the head, summit, from vertere to turn

noun

  1. the top of the head

  2. the point opposite to and farthest from the base in a figure

  3. a point (as of an angle, polygon, polyhedron, graph, or network) that terminates a line or curve or comprises the intersection of two or more lines or curves