Outfit a huge hit (7)
I believe the answer is:
clobber
'hit' is the definition.
(I've seen this before)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for clobber that I've seen before include "Clothes (slang);hit hard" , "Hit; gear (sl.)" , "belt or > sock" , "Kit" , "Tackle" .)