means a bet — money or stakes risked on the uncertain outcome of something, or the act of placing such a bet.

from From the Anglo-Norman 'wageure,' built on 'wager' meaning to pledge or promise, which traces back to a Frankish root related to 'gage' — a pledge or pawn. That same family gives us 'wage' (the pledge of pay for work) and 'engage' (to bind by promise), so betting your shirt and earning your paycheck are distant cousins, both rooted in the idea of giving your word as security.