A lessor is the owner who lets someone else use their house, building, or land for a time, in return for payment. They do not sell it; they keep it and collect the rent or the lease money. Like lessee, this is a lawyer’s word. Most people say landlord, landlady, or owner. In a lease, the lessor is one side and the lessee is the other. It comes from Middle English lessour, from Anglo-Norman lessour — the same family as lease and lessee. A quick way to hold it: the lessor is the source of the lease, the one who lets the place out.