Start to produce amateur drama (4)
I believe the answer is:
play
'drama' is the definition.
('play' can be a synonym of 'drama')
'start to produce amateur' is the wordplay.
'start to' says to take the initial letters.
'amateur' becomes 'lay' ('lay' can be similar in meaning to 'amateur').
The initial letter of 'produce' is 'p'.
'p'+'lay'='PLAY'
(Other definitions for play that I've seen before include "Theatre performance" , "Stage work" , "Scope - entertainment" , "Perform music" , "stage production" .)