Money received once I'm working (6)
I believe the answer is:
income
'money received' is the definition.
(I've seen this before)
'once i'm working' is the wordplay.
'working' is an anagram indicator.
'once'+'im'='onceim'
'onceim' with letters rearranged gives 'INCOME'.
(Other definitions for income that I've seen before include "Money received as wages, interest etc" , "Money gained from work or investment" , "What do you make" , "Money gained over time" , "Wage" .)