Cat fight being topless (4)
I believe the answer is:
lash
'cat' is the definition.
(I've seen this before)
'fight being topless' is the wordplay.
'fight' becomes 'clash' (clash is a kind of fight).
'being topless' means to remove the first letter.
'clash' with its initial letter taken away is 'LASH'.
(Other definitions for lash that I've seen before include "cat hair?" , "Beat; fasten with cord" , "Hit with a whip" , "Stroke of the whip" , "Sweep" .)