Rent payer (6)
I believe the answer is:
lessee
'rent payer' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for lessee that I've seen before include "One holding lease on property" , "Leaseholder" , "Person renting a property" , "I have to deal with letter" , "One renting a property" .)