Spanish conquistador (6)
I believe the answer is:
cortez
'spanish conquistador' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for cortez that I've seen before include "Spaniard who defeated the Aztecs and conquered Mexico" , "Spanish conquistador Keats had 'Silent, upon a peak in Darien'" , "Spanish conquistador (Z, not S)" .)