WordNet (r) 3.0 (2006):

stock warrant
    n 1: 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" [syn:
         warrant, stock warrant, stock-purchase warrant]
    2: a written certificate that gives the holder the right to
       purchase shares of a stock for a specified price within a
       specified period of time