1. A contractual clause containing a warranty.
2. Oil & gas. A provision in an oil-and-gas lease by which the lessor guarantees that title is without defect and agrees to defend it. • If the warranty is breached, the lessor may be held liable to the lessee to the extent that the lessor has received payments under the lease. Presence of a warranty in an oil-and-gas lease may also cause after-acquired interests to pass from the lessor to the lessee by application of estoppel by deed.