| the principles and rules, drawn chiefly from custom, determining the rights and obligations of commercial transactions; commercial law. |

| law merchant n. pl. laws merchant A body of principles and regulations applied to commercial transactions and deriving from the established customs of merchants and traders rather than the jurisprudence of a particular nation or state. |
law merchant
during the Middle Ages, the body of customary rules and principles relating to merchants and mercantile transactions and adopted by traders themselves for the purpose of regulating their dealings. Initially, it was administered for the most part in special quasi-judicial courts, such as those of the guilds in Italy and, later, regularly constituted piepoudre courts in England (see piepoudre court).
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