S: (n) warrant, stock warrant, stock-purchase warrant (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"
S: (n) assurance, pledge (a binding commitment to do or give or refrain from something) "an assurance of help when needed"; "signed a pledge never to reveal the secret"
S: (v) warrant (provide adequate grounds to justify (a certain course of action)) "The emergency does not warrant all of us buying guns"
S: (v) guarantee, warrant (stand behind and guarantee the quality, accuracy, or condition of) "The dealer warrants all the cars he sells"; "I warrant this information"