Mechanic (8)
(Other definitions for operator that I've seen before include "Switchboard worker" , "Person who directs or controls, machine say (8)." , "Controller, of a machine say" , "Person at switchboard, etc" , "Poor rate for a businessman" .)
'mechanic' is the definition.
(type of engineer)
This is the entire clue.
(Other definitions for engineer that I've seen before include "One who designs, makes or runs motors" , "Cleverly bring about" , "control" , "One who designs/builds" , "Professional who may be civic, electrical or mechanical" .)
'mechanic' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for greaser that I've seen before include "An unctuous individual" , "(Unskilled) mechanic" , "Biker" , "Mechanic - sycophant" , "Ship's engineer; motor mechanic" .)