He sold his soul to the Devil (5)
I believe the answer is:
faust
'he sold his soul to the devil' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for faust that I've seen before include "Goethe's two-part tragedy" , "Tragic figure" , "Alchemist" , "Goethe play" , "Opera" .)