Topmost point (8)
'topmost point' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for pinnacle that I've seen before include "Apogee" , "Highest point (of fame or building)" , "Crown" , "The highest level" , "Topmost point" .)
'topmost point' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for apex that I've seen before include "Summit - pinnacle" , "Acme" , "The tip or highest point (4)" , "Top, highest part" , "The highest point of something" .)