Part of engine unaffected by reversal (5)

I believe the answer is:

rotor

I believe this clue is a double definition.

'part of engine' is the first definition.

'unaffected by reversal' is the second definition.

(Other definitions for rotor that I've seen before include "Revolving component" , "Turning component" , "Copter blade assembly" , "Revolving arm in machine" , "Helicopter propeller" .)

I've seen this clue in The Times.

Want a hint initially instead of a full solution? Install my app