Actor playing a small part in the next race? (5)
I believe the answer is:
extra
'actor' is the definition.
(extra is a type of actor)
'in the next race?' is the wordplay.
'in' says the answer is hidden in the clue.
'EXTRA' is hidden in the letters of 'next race'.
'playing a small part' is the link.
This may not be right. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for extra that I've seen before include "Auxiliary" , "Bonus; surplus" , "Small part actor" , "entry on scorecard?" , "special edition of the paper" .)