Arrived with Oscar for small role (5)
I believe the answer is:
cameo
'small role' is the definition.
(I've seen this before)
'arrived with oscar' is the wordplay.
'arrived' becomes 'came' (come can mean to appear or arrive).
'with' means one lot of letters go next to another.
'oscar' becomes 'O' (phonetic alphabet: alpha, bravo, charlie etc.).
'came'+'o'='CAMEO'
'for' is the link.
(Other definitions for cameo that I've seen before include "Small piece of hard stone carved with raised design" , "Short performance" , "Brooch with an engraving in low relief" , "Famous actor's small role" , "relief work" .)