vertex

noun12

1. •
   The highest point, top or apex of something.

   • The mountain’s vertex was covered in snow.
   • He reached the vertex of his career after decades of work.
2. •
   An angular point of a polygon, polyhedron or higher order polytope.
3. •
   The common point of the two rays that form an angle.
4. •
   A sharp downward point opposite a crotch, as in the letters "V" and "W" but not "Y".
5. •
   One of the elements of a graph joined or not by edges to other vertices.
6. •
   The highest surface on the skull; the crown of the head.
7. •
   A point in 3D space, usually given in terms of its Cartesian coordinates.
8. •
   The point at which an axis meets a curve or surface.
9. •
   A point on the curve with a local minimum or maximum of curvature.
10. •
    The point where the surface of a lens crosses the optical axis.
11. •
    An interaction point.
12. •
    The point where the prime vertical meets the ecliptic in the western hemisphere of a natal chart.