Minotaur slayer (7)
I believe the answer is:
theseus
'minotaur slayer' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for theseus that I've seen before include "Mythical hero" , "authority in the D [DREAM]" , "Founder-hero of Athens" , "Ariadne's abandoner" , "Rescuer of Ariadne" .)