Clobber on, cuter after tailoring (7)
I believe the answer is:
trounce
'clobber' is the definition.
(I know that clobber is a more specific form of the action the trounce)
'on cuter after tailoring' is the wordplay.
'after tailoring' is an anagram indicator.
'on'+'cuter'='oncuter'
'oncuter' anagrammed gives 'TROUNCE'.
(Other definitions for trounce that I've seen before include "Easily best" , "Defeat decisively" , "Beat hollow" , "Beat heavily" , "Hammer" .)