Mounted bullfighter (7)
I believe the answer is:
picador
'mounted bullfighter' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for picador that I've seen before include "The bullfighter who goads the animal" , "Riding bullfighter" , "Horseman in bullring" , "Animal killer" , "fighter with lance" .)