What is Ad Terminum Qui Preterit?

Legal Definition
For a term which has passed. Words in the Latin form of the writ of entry employed al common law to recover, on behalf of a landlord, possession of premises, from a tenant holding over after the expiration of the term for which they were demised. See Fitzh. Nat. Brev. 201.
-- Black's Law Dictionary
Legal Definition
A writ which the lessor could use to secure possession when refused by the lessee after the expiration of his lease.
-- Ballentine's Law Dictionary