Claps about trophy (5)
I believe the answer is:
scalp
'trophy' is the definition.
(I've seen this before)
'claps about' is the wordplay.
'about' indicates an anagram.
'claps' is an anagram of 'SCALP'.
(Other definitions for scalp that I've seen before include "Trophy signifying conquest" , "wants to resell theatre tickets" , "Skin covering top of the head" , "Hair producer" , "Token of victory" .)