Propeller part (5)
I believe the answer is:
blade
'propeller part' is the definition.
('blade' is part of 'propeller')
This is the entire clue.
(Other definitions for blade that I've seen before include "Flat part of an oar" , "See 24 Across" , "Runner on an ice-skate" , "Cutting edge" , "A knife, or a dashing fellow" .)