A cop bust the female thief (7)
I believe the answer is:
poacher
'thief' is the definition.
(poacher is a kind of thief)
'a cop bust the female' is the wordplay.
'bust' is an anagram indicator.
'the female' becomes 'her' (I've seen this before).
'a'+'cop'='acop'
'acop' with letters rearranged gives 'poac'.
'poac'+'her'='POACHER'
(Other definitions for poacher that I've seen before include "Gamekeeper's enemy" , "in the kitchen?" , "Stealer of game" , "Gamekeeper's opponent" , "Illegal game hunter" .)