Renter has smaller amount midweek (6)
I believe the answer is:
lessee
'renter' is the definition.
(lessee is a kind of renter)
'smaller amount midweek' is the wordplay.
'smaller amount' becomes 'less' (I've seen this before).
'midweek' becomes 'ee'.
'less'+'ee'='LESSEE'
'has' is the link.
(Other definitions for lessee that I've seen before include "Who pays the rent" , "One holds a lease" , "I have to deal with letter" , "Contractor" , "Leaseholder" .)