n Something that provides assurance or confirmation; a guarantee or proof: a warrant of authenticity; a warrant for success.
n An order that serves as authorization, especially: A voucher authorizing payment or receipt of money.
n (legal) A judicial writ authorizing an officer to make a search, seizure, or arrest or to execute a judgment.
n A warrant officer.
n A certificate of appointment given to a warrant officer.
n (finance) An option, usually with a term at issue greater than a year, usually issued together with another security, to buy other securities of the issuer.
n (New Zealand) A Warrant of Fitness; a document certifying that a motor vehicle meets certain standards of safety and mechanical soundness.
v (obsolete|transitive) To protect, keep safe (from danger).
v (transitive) To guarantee (something) to be (of a specified quality, value etc.).
v (transitive) To guarantee as being true; (qualifier|colloquially) to believe strongly.
v (obsolete|transitive) To give (someone) a guarantee or assurance (of something); also, with double object, to guarantee (someone something).
v (transitive) To authorize; to give (someone) warrant or sanction (to do something).