Black's Law Dictionary (2nd edition)dictionaries

Unwritten Law

All that portion of the law, observed and administered in the courts, which hns not been enacted or promulgated in the form of a statute or or-dinance, including the anenacted portions of the common lnw, general and particular customs having the force of law, and the rules, principles, and maxims established by Ju-dicial precedents or the successive like de-cisions of the courts. See Code Civ. Proc. Cal. 1903, $ 1899; B. & C. Comp. or. 1901, | 736

Source: Black's Law Dictionary 2nd Ed (1910)