Play divisions (4)
I believe the answer is:
'play divisions' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for acts that I've seen before include "Pieces of legislation" , "religious work" , "the entertainment for a revue?" , "[BOOK] of the 26 [BIBLE]" , "New Testament book immediately following the Gospels" .)