Minor role (3,4)
'minor role' is the definition.
(synonyms)
This is all the clue.
(Other definitions for bit part that I've seen before include "Small acting role" , "Tiny or non-speaking dramatic role" , "'Small role in film or play (3,4)'" , "Very minor role" , "extra work, perhaps" .)
'minor role' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for cameo that I've seen before include "E. Med. nation" , "Something small but well done - say role in play" , "Medallion with a profile carved in relief" , "Brief role" , "Item of jewellery with a portrait - distinguished actor's minor role" .)