guaranty

n. (pl. -ies) 1 written or other undertaking to answer for the payment of a debt or for the performance of an obligation by another person liable in the first instance. 2 thing serving as security.

n. In law and common usage: An undertaking to answer for the payment of some debt, or the performance of some contract or duty, of another, in case of the failure of such other to pay or perform; a guarantee; a warranty; a security.