Moulded actors taking part in play (4)

I believe the answer is:
cast
'play' is the definition.
(cast is a kind of play)
'moulded actors taking part' is the wordplay.
'moulded actors' becomes 'cas' (I am not sure about this - if you are sure you should believe this answer much more).
'part' indicates taking the first letters.
The first letter of 'taking' is 't'.
'cas'+'t'='CAST'
'in' acts as a link.
Can you help me to learn more?
(Other definitions for cast that I've seen before include "Discard; actors (in play)" , "Allot roles in a play" , "In which player" , "Throw off; select (actor)" , "'Ne'er .... a clout till May be out'" .)
