martingale

mar·tin·gale   (mär'tn-gāl')    n.   The strap of a horse's harness that connects the girth to the noseband and is designed to prevent the horse from throwing back its head. Nautical Any of several parts of standing rigging strengthening the bowsprit and jib boom against the force of the head stays. Games A method of gambling in which one doubles the stakes after each loss. A loose half belt or strap placed on the back of a garment, such as a coat or jacket. [French, perhaps alteration of Spanish almártaga, almártiga, rein, harness, perhaps of Arabic origin.]

Martingale

Mar"tin*gale\, Martingal \Mar"tin*gal\, n. [F. martingale; cf. It. martingala a sort of hose, martingale, Sp. martingala a greave, cuish, martingale, Sp. alm['a]rtaga a kind of bridle.]

1. A strap fastened to a horse's girth, passing between his fore legs, and fastened to the bit, or now more commonly ending in two rings, through which the reins pass. It is intended to hold down the head of the horse, and prevent him from rearing.

2. (Naut.) A lower stay of rope or chain for the jib boom or flying jib boom, fastened to, or reeved through, the dolphin striker. Also, the dolphin striker itself.

3. (Gambling) The act of doubling, at each stake, that which has been lost on the preceding stake; also, the sum so risked; -- metaphorically derived from the bifurcation of the martingale of a harness. [Cant] --Thackeray.