Merriam-Webster's Collegiate® Dictionary, 11th Edition
WAGER
I. noun
Etymology: Middle English wageour pledge, bet, from Anglo-French wageure, from *wager
Date: 14th century
1. something (as a sum of money) risked on an uncertain event ; stake , something on which bets are laid ; gamble , an act of giving a pledge to take and abide by the result of some action,
II. verb (wagered; wagering)
Date: 1602
intransitive verb to make a bet, transitive verb to risk or venture on a final outcome, wagerer noun