Rent since collected by general (5)
I believe the answer is:
lease
'rent' is the definition.
(I know that rent can be written as lease)
'since collected by general' is the wordplay.
'since' becomes 'as' (I've seen this in other clues).
'collected by' indicates putting letters inside.
'general' becomes 'lee' (Robert E. Lee - US revolutionary commander).
'as' put inside 'lee' is 'LEASE'.
(Other definitions for lease that I've seen before include "Let for money" , "Tenancy contract" , "Hire out, rent" , "Property rental agreement" , "Rent -- easel (anag)" .)