Part of the engine to spin round (6)
I believe the answer is:
piston
'part of the engine' is the definition.
'piston' can be an answer for 'engine' (thesaurus). I am unsure of the 'part of the' bit.
'to spin round' is the wordplay.
'round' indicates anagramming the letters.
'to'+'spin'='tospin'
'tospin' with letters rearranged gives 'PISTON'.
Can you help me to learn more?
(Other definitions for piston that I've seen before include "Mechanical plunger" , "Part of a machine with a plunging motion" , "Transmitter of motion from camshaft to valve" , "Brass instrument's valve" , "Driving rod in engine" .)