Pronunciation: (mär'tn-gāl"),[key] —n. 1. Also calledstanding martingale. part of the tack or harness of a horse, consisting of a strap that fastens to the girth, passes between the forelegs and through a loop in the neckstrap or hame, and fastens to the noseband: used to steady or hold down the horse's head. See illus. under harness. 2. Also calledrunning martingale. a similar device that divides at the chest into two branches, each ending in a ring through which the reins pass.
3. Naut.a stay for a jib boom or spike bowsprit.
4. a system of gambling in which the stakes are doubled or otherwise raised after each loss.