(1):
(n.) 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.
(2):
(n.) The person to whom a guaranty is made; - the correlative of guarantor.
(3):
(n.) One who binds himself to see an undertaking of another performed; a guarantor.
(4):
(n.) In law and common usage: to undertake or engage for the payment of (a debt) or the performance of (a duty) by another person; to undertake to secure (a possession, right, claim, etc.) to another against a specified contingency, or at all avents; to give a guarantee concerning; to engage, assure, or secure as a thing that may be depended on; to warrant; as, to guarantee the execution of a treaty.