Times chasing copy from summit (4)
I believe the answer is:
apex
'summit' is the definition.
(thesaurus)
'times chasing copy' is the wordplay.
'times' becomes 'x' (multiplication sign).
'chasing' is a charade indicator (letters next to each other).
'copy' becomes 'ape' ('ape' can be a synonym of 'copy').
'x' after 'ape' is 'APEX'.
'from' acts as a link.
(Other definitions for apex that I've seen before include "Apogee, summit" , "The highest point of something" , "Top, highest part" , "climax" , "Summit or peak" .)