Awkward person puts it in propeller (3)
I believe the answer is:
oar
This clue is a double definition.
'awkward person puts it in' is the first definition.
(an interfering person 'sticks their oar in')
'propeller' is the second definition.
(I've seen this before)
(Other definitions for oar that I've seen before include "Bladed pole" , "propellor" , "Manual boat propeller" , "It ends in blade" , "Implement to propel a boat" .)