1911 Encyclopædia Britannica/Gage

GAGE, a pledge, something deposited as security for the performance of an agreement, and liable to be forfeited on failure to carry it out. The word also appears in “engage,” and is taken from the O. Fr., as are “wage,” payment for services, and “wager,” bet, stake, from the collateral O. Fr. waige. These two words are from the Low Lat. wadiare, vadiare, to pledge, vadium, classical Lat. vas, vadis, but may be from the old Teutonic cognate base seen in Gothic wadi, a pledge (cf. Ger. wetten, to wager); this Teutonic base is seen in Eng. “wed,” to marry, i.e. to engage by a pledge (cf. Goth. gawadjon, to betrothe). A particular form of giving a “gage” or pledge was that of throwing down a glove or gauntlet as a challenge to a judicial combat, the glove being the “pledge” that the parties would appear on the field; hence the common phrase “to throw down the gage of defiance” for any challenge (see Glove and Wager).