Guar·an·tee n.; pl. Guarantees
1. In law and common usage: A promise to answer for the payment of some debt, or the performance of some duty, in case of the failure of another person, who is, in the first instance, liable to such payment or performance; an engagement which secures or insures another against a contingency; a warranty; a security. Same as Guaranty.
His interest seemed to be a guarantee for his zeal. --Macaulay.
2. One who binds himself to see an undertaking of another performed; a guarantor.
Note: ☞ Guarantor is the correct form in this sense.
3. Law The person to whom a guaranty is made; -- the correlative of guarantor.
Syn: -- Guarantee, Warranty.
Usage: A guarantee is an engagement that a certain act will be done or not done in future. A warranty is an engagement as to the qualities or title of a thing at the time of the engagement.