apexn.[L.]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.()n.[L.] Same as Apheresis.()adj.1. relating to or formed by or consisting of aphaeresis.()n.[NL.; Gr. 'a priv. + seed of a lentil.] (Med.) An anomalous state of refraction caused by the absence of the crystalline lens, as after operations for cataract. The remedy is the use of powerful convex lenses.(Dunglison.)