Apex
Part of speech: noun
Definition: The highest point of something. The moment of greatest success, expansion, etc. The topmost vertex of a cone or pyramid (in their conventional orientation). The pointed end of something. # The lowest part of the human heart. # The deepest part of a tooth's root. The end of a leaf, petal or similar organ opposed to the end where it is attached to its support; the tip.
Example sentence: Life is apogee, apex, decline; life is death - and everything else is open to discussion.
Acme
Part of speech: noun
Definition: The top or highest point; pinnacle; culmination.The crisis or height of a disease.Mature age; full bloom of life. - Ben Jonson