"a pledge, a pawn, something valuable deposited to insure performance," especially "something thrown down as a token of challenge," c.1300, from Old French gage "pledge (of battle), security, guarantee; pay, reward" (11c.), from Frankish *wadja-, from Proto-Germanic *wadi- (see wed). Italian gaggio, Spanish and Portuguese gage are French loan-words.

c.1400, "to deposit as security," from Old French gager, gagier "to guarantee, promise, pledge, swear; bet, wager; pay," from gage "security, pledge" (see gage, n.). Related: Gaged; gaging. For the measuring sense, see gauge, v..