Driver seen in Mastermind ? (8)
I believe the answer is:
engineer
This clue is a double definition.
'driver' is the first definition.
(thesaurus)
'mastermind ?' is the second definition.
('engineer' can be a synonym of 'mastermind ')
'seen in' acts as a link.
(Other definitions for engineer that I've seen before include "Bring about, being skilled in machinery" , "Train driver, say" , "Skilled professional - electrical, civil or mechanical" , "Professional who uses scientific knowledge to solve practical problems" , "One can be chemical, civil or mechanical" .)