Machinist or surgeon? (8)
I believe the answer is:
operator
I believe this clue is a double definition.
'machinist' is the first definition.
(I've seen this before)
'surgeon?' is the second definition.
(thesaurus)
'or' is the link.
(Other definitions for operator that I've seen before include "Mechanic" , "Mathematical symbol" , "Person who directs or controls, machine say (8)." , "Driver" , "Person at switchboard, etc" .)