Produce work on credit! (4)
I believe the answer is:
crop
'produce' is the definition.
(I've seen this in another clue)
'work on credit' is the wordplay.
'work' becomes 'op' (common abbreviation for 'opus').
'on' says to put letters next to each other.
'credit' becomes 'cr' (abbreviation).
'op' after 'cr' is 'CROP'.
(Other definitions for crop that I've seen before include "Cut short the harvest" , "supply" , "Type of whip" , "The yield, from cereals say" , "Hunting whip" .)