guarantee
guar·an·tee / ˌgarənˈtē/ • n. a formal promise or assurance (typically in writing) that certain conditions will be fulfilled, esp. that a product will be repaired or replaced if not of a specified quality and durability: we offer a 10-year guarantee against rusting. ∎ something that gives a certainty of outcome: past performance is no guarantee of future results. ∎ variant spelling of guaranty. ∎ less common term for guarantor.• v. (-tees, -teed, -tee·ing) [intr.] provide a formal assurance or promise, esp. that certain conditions shall be fulfilled relating to a product, service, or transaction: the con artist guarantees that the dirt pile will yield at least 20 ounces of gold. ∎ [tr.] provide such an assurance regarding (something, esp. a product): the repairs will be guaranteed for three years | [as adj.] (guaranteed) the guaranteed bonus is not very high. ∎ [tr.] provide financial security for; underwrite: a demand that $100,000 be deposited to guarantee their costs. ∎ [tr.] promise with certainty: no one can guarantee a profit on stocks.
guaranty
guar·an·ty / ˈgarənˌtē/ (also guar·an·tee) • n. (pl. -ties) a formal pledge to pay another person's debt or to perform another person's obligation in the case of default. ∎ a thing serving as security for a such a pledge.
Guaranty
GUARANTY
As a verb, to agree to be responsible for the payment of another's debt or the performance of another's duty, liability, or obligation if that person does not perform as he or she is legally obligated to do; to assume the responsibility of a guarantor; to warrant.
As a noun, an undertaking or promise that is collateral to the primary or principal obligation and that binds the guarantor to performance in the event of nonperformance by the principal obligor.
A guaranty is a contract that some particular thing shall be done exactly as it is agreed to be done, whether it is to be done by one person or another, and whether there be a prior or principal contractor or not.
guarantor
guar·an·tor / ˌgarənˈtôr; ˈgarəntər/ • n. a person, organization, or thing that guarantees something: the role of the police as guarantors of public order. ∎ Law a person or organization who provides a guaranty.
guarantee
Hence as vb. be a guarantee for XVIII; secure (a person or thing) in possession XIX.