Badly bruised (5,3,4)
I believe the answer is:
black and blue
'badly bruised' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for black and blue that I've seen before include "as are NZ and Scottish rugby teams?" , "Badly bruised" , "looking thoroughly beaten?" , "two balls at snooker" , "How one might be seen after striking" .)