The highest point; the vertex.
The apex of a triangle; the apex of a hill.
The highest level or degree that is attained.
The highest point of interest, excitement, etc.; climax.
The highest point; peak; vertex.
The highest point, especially the vertex of a triangle, cone, or pyramid.
The pointed end; tip.
(mining) The edge or outcrop of a vein nearest the surface.
The usually pointed end of an object; the tip.
The apex of a leaf.
The definition of apex is the highest part of something.
The peak of a mountain is an example of its apex.
(UK, trade union) Association of Professional, Executive, Clerical and Computer Staff.
Origin of apex
From American Heritage Dictionary of the English Language, 5th Edition