Permissive landlord? (6)
I believe the answer is:
letter
'landlord?' is the definition.
(landlords let property)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for letter that I've seen before include "Epistle, missive" , "Character of the alphabet" , "Piece of correspondence" , "Communication via the postman" , "Item sent - character" .)