Brings in (5)
'brings in' is the definition.
('earn' can be a synonym of 'bring in')
This is all the clue.
(Other definitions for earns that I've seen before include "Gains by work" , "Makes - deserves (by one's efforts)" , "makes money" , "Gains by labour" , "Acquires by effort" .)
'brings in' is the definition.
(grossing is a kind of bringing in)
This is the entire clue.