martingale noun 5verb 1forms 3 noun5 •A stochastic process for which the conditional expectation of future values given the sequence of all prior values is equal to the current value.If a gambler plays a fair game repeatedly, his payoff over time is a martingale. •A strategy in which one doubles the stake after each loss. •A piece of harness used on a horse to keep it from raising its head above a desired point.I’ll be bound, Lady Ashton understands every machine for breaking in the human mind, and there are as many as there are cannon-bit, martingales, and cavessons for young colts. — 1819 •A spar, or piece of rigging that strengthens the bowsprit. •A strap attached to the sword handle, preventing a sword being dropped if disarmed. verb1 •To employ the martingale strategy in gambling.The Russians were both martingaling it—doubling their bets when they lost. — 2012 formsmartingaled · martingaling · martingales