Produce in order to earn (4)
I believe the answer is:
make
I believe this clue is a triple definition!
'produce' is the first definition.
(I know that produce is a kind of make)
'in' acts as a link.
'order' is the second definition.
(thesaurus)
'to earn' is the third definition.
('make' can be a synonym of 'earn')
(Other definitions for make that I've seen before include "Create; a brand" , "Fabricate" , "Keep the wolf from the door?" , "Manufacture, form" , "Create or cause to happen" .)