apex
UK[ˈeɪ.peks]US[ˈeɪ.peks]
n
The top or highest part of something, especially one forming a point.
n
The highest point of achievement or development.
Etymology
The word 'apex' was borrowed directly from Latin, where it meant 'peak, tip, summit, or top point'. In Latin, it could refer specifically to the pointed end of a priest's cap or the tip of a flame. The term is thought to be derived from the Proto-Indo-European root ap-, meaning 'to take, reach, or grasp', which conceptually relates to the idea of attaining the highest point. Over time, its meaning evolved from a purely physical 'pointed top' to also signify the pinnacle or climax of abstract concepts like a career, an era, or an event.
Analysis
The word 'apex' is a simplex loanword from Latin. It does not contain separable morphemes in its modern English spelling.
Examples
The rocket reached the apex of its trajectory before beginning its descent.
Winning the championship was the apex of her athletic career.
The apex of the triangle is opposite its longest side.