Actors made of plaster? (4)
I believe the answer is:
cast
I believe this clue is a triple definition!
'actors' is the first definition.
(group of actors)
'made' is the second definition.
(thesaurus)
'of' acts as a link.
'plaster?' is the third definition.
(thesaurus)
(Other definitions for cast that I've seen before include "discarded" , "Throw out line for fish" , "Register (a vote)" , "Throw off; select (actor)" , "Shed - actors" .)