Top primate with Times (4)
I believe the answer is:
apex
'top' is the definition.
(apex is a top or peak)
'primate with times' is the wordplay.
'primate' becomes 'ape' (large primate).
'with' is a charade indicator (letters next to each other).
'times' becomes 'x' (p times 4 is p x 4).
'ape'+'x'='APEX'
(Other definitions for apex that I've seen before include "Peak, vertex" , "Uppermost tip" , "The highest point of something" , "Absolute peak" , "Topmost point" .)