The one who kills the bull (7)
I believe the answer is:
matador
'the one who kills the bull' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for matador that I've seen before include "fighter in the ring?" , "The one who kills the bull" , "he aims to get a bull" , "Spaniard that fights" , "Spanish killer" .)