Apex

n. pl. E. Apexes (); L. Apices ().

1. The tip, top, point, or angular summit of anything; as, the apex of a mountain, spire, or cone; the apex, or tip, of a leaf.
2. (Mining) The end or edge of a vein nearest the surface.
Apex of the earth's motion (Astron.),
that point of the heavens toward which the earth is moving in its orbit.