Guaranty

Guar"an*ty (?), n.; pl. Guaranies (#). [OF. guarantie, garantie, F. garantie, OF. guarantir, garantir, to warrant, to guaranty, E. garantir, fr. OF. guarant, garant, a warranter, F. garant; of German origin, and from the same word as warranty. See Warrant, and cf. Warranty, Guarantee.] 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.

Guar"an*ty, v. t. [imp. & p. p. Guarantied (?); p. pr. & vb. n. Guarantying.] [From Guaranty, n.] In law and common usage: To undertake or engage that another person shall perform (what he has stipulated); to undertake to be answerable for (the debt or default of another); to engage to answer for the performance of (some promise or duty by another) in case of a failure by the latter to perform; to undertake to secure (something) to another, as in the case of a contingency. See Guarantee, v. t.

Guaranty agrees in form with warranty. Both guaranty and guarantee are well authorized by legal writers in the United States. The prevailing spelling, at least for the verb, is guarantee.