Ship's propeller (5)
I believe the answer is:
screw
'ship's propeller' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for screw that I've seen before include "Fastener with a tapered threaded shank" , "Fastener, rivet" , "The Turn of the ___ , 1898 Henry James horror story" , "Metal fastener" , "one on prison door?" .)