Rubbish or Turner? (5)
I believe the answer is:
rotor
'turner?' is the definition.
(something that turns)
'rubbish or' is the wordplay.
'rubbish' becomes 'rot' (both can mean nonsense).
'rot'+'or'='ROTOR'
(Other definitions for rotor that I've seen before include "one lifting chopper?" , "Turning part of a mechanism" , "The machine part moves in a circle" , "Reversible piece of moving machinery?" , "Revolving component" .)