Akademik

martingale
n.
1 a strap, or set of straps, fastened at one end to the noseband of a horse and at the other end to the girth, to prevent rearing etc.
2 Naut. a rope for holding down the jib-boom.
3 a gambling system of continually doubling the stakes in the hope of an eventual win that must yield a net profit.
Etymology: F, of uncert. orig.

Useful english dictionary. 2012.