Black's Law Dictionary (2nd edition)dictionaries

Debet Et Detinet

He owes and de-tains. words anciently used in the original writ, (aud now, in English, in the plaintiff's declaration,) in an action of debt, where it was brought by one of the original contract-ing parties who personally gave the credit, against the other who personally incurred the debt, or against his heirs, if they were bound to the payment; as hy the obligee against the obligor, by the landlord agninst the tenant, etc. The declaration, in such cases, states that the defendant “owes to,” as well as “detains from,” the plaintiff the debt or thing iu question; and hence the action is said to be “in the debef et detinct." where the declaration merely states that the defendant detains the debt, (as in actions by and against an executor for a debt due to or from the testator,) the action is said to be “in the detinct" alone. Fltzh. Nat. Brev. 119, G.; 3 Bl. Comm. 155

Source: Black's Law Dictionary 2nd Ed (1910)