Use badly and prosecute (3)
I believe the answer is:
sue
'prosecute' is the definition.
(I've seen this before)
'use badly' is the wordplay.
'badly' indicates anagramming the letters (letters in the wrong order).
'use' anagrammed gives 'SUE'.
'and' is the link.
(Other definitions for sue that I've seen before include "The girl to take to court" , "Susan (dim.)" , "Litigious girl" , "Use to take to court" , "Take case against in court" .)