Be a breadwinner (4)
I believe the answer is:
earn
'be a breadwinner' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for earn that I've seen before include "Take in bread" , "Gain by work or effort" , "and 3: Work for bed and board" , "Take home" , "Near (anag.)" .)