Minor alternative landlord (6)
I believe the answer is:
lessor
'landlord' is the definition.
(I've seen this before)
'minor alternative' is the wordplay.
'minor' becomes 'less' (I've seen this before).
'alternative' becomes 'or'.
'less'+'or'='LESSOR'
(Other definitions for lessor that I've seen before include "The granter of a lease" , "One granting a lease" , "Landlord" , "One lets" , "The one who grants a lease" .)