What does "martingal" mean?

Martingal: (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.

Additional senses

  1. 2.(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.

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