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