Walk-on part (4)
(Other definitions for sole that I've seen before include "piece of leather" , "Unique" , "Flatfish; exclusive" , "Fish; part of foot" , "fish in the sea!" .)
(Other definitions for cameo that I've seen before include "Carved head on gem - short dramatic role for star" , "Short performance" , "Small part for star actor" , "Piece of jewellery; small role" , "Part in movie" .)