Definition of "Warrant" :

noun: a writ from a court commanding police to perform specified acts

noun: a written assurance that some product or service will be provided or will meet certain specifications

noun: formal and explicit approval

noun: a type of security issued by a corporation (usually together with a bond or preferred stock) that gives the holder the right to purchase a certain amount of common stock at a stated price

"As a sweetener they offered warrants along with the fixed-income securities."

verb: stand behind and guarantee the quality, accuracy, or condition of

"The dealer warrants all the cars he sells."

verb: provide adequate grounds to justify (a certain course of action)

"The emergency does not warrant all of us buying guns."