One who holds a lease (a tenancy).

(by extension) One who has possession of any place.

(computing) Any of a number of customers serviced through the same instance of an application.

(chiefly historical) One who holds a feudal tenure in real property.

(property law, by extension) One who owns real estate other than via allodial title.

Misconstruction of tenet

To hold as, or be, a tenant.

(transitive) To inhabit.