By"-law` (), n. [Cf.Sw.bylag, D.bylov, Icel.barlog, fr.Sw.& Dan. by town, Icel. baer, byr (fr. bua to dwell) + the word for law; hence, a law for one town, a special law. Cf.Birlaw and see Law.]
1.
A local or subordinate law; a private law or regulation made by a corporation for its own government.
There was likewise a law to restrain the by-laws, or ordinances of corporations.
Bacon.
The law or institution; to which are added two by-laws, as a comment upon the general law.
Addison.
2.
A law that is less important than a general law or constitutional provision, and subsidiary to it; a rule relating to a matter of detail; as, civic societies often adopt a constitution and by-laws for the government of their members. In this sense the word has probably been influenced by by, meaning secondary or aside.
© Webster 1913.