Definitions for "By-law"
A local or subordinate law; a private law or regulation made by a corporation for its own government.
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.
A rule or regulation. Cc