Source : Webster's Revised Unabridged Dictionary (1913)

Gamble \Gam"ble\, n.
   An act of gambling; a transaction or proceeding involving
   gambling; hence, anything involving similar risk or
   uncertainty. [Colloq.]

Gamble \Gam"ble\, v. i. [imp. & p. p. {Gambled}; p. pr. & vb. n.
   {Gambling}.] [Dim. of game. See 2d {Game}.]
   To play or game for money or other stake.

Gamble \Gamble\, v. t.
   To lose or squander by gaming; -- usually with away.
   ``Bankrupts or sots who have gambled or slept away their
   estates.'' --Ames.

Source : WordNet®

gamble
     n 1: money that is risked for possible monetary gain
     2: a risky act or venture

gamble
     v 1: take a risk in the hope of a favorable outcome; "When you
          buy these stocks you are gambling" [syn: {chance}, {risk},
           {hazard}, {take chances}, {adventure}, {run a risk}, {take
          a chance}]
     2: play games for money