Lex \Lex\ (l[e^]ks), n.; pl. {Leges} (l[=e]"j[=e]z). [L. See {Legal}.] Law; as, lex talionis, the law of retaliation; lex terr[ae], the law of the land; lex fori, the law of the forum or court; lex loci, the law of the place; lex mercatoria, the law or custom of merchants. [1913 Webster]