Something used in a supporting role? (4)
I believe the answer is:
prop
'something used' is the definition.
I can't judge whether this definition defines the answer.
'a supporting role?' is the wordplay.
'a supporting' becomes 'pro' (I've seen this in other clues).
'role?' becomes 'p' (I can't explain this - if you can you should give a lot more credence to this answer).
'pro'+'p'='PROP'
'in' acts as a link.
Can you help me to learn more?
(Other definitions for prop that I've seen before include "Driving mechanism" , "Lean" , "Moveable object used on stage" , "Stay" , "Support; object used on stage" .)