Definition from Wiktionary, the free dictionary
Alteration of byrlaw, but popularly interpreted as by- (“town”) + law (though, to be fair, this isn't exactly false, as -by is a derivative of Old Norse býr). Compare Danish bylov (“municipal law”).
bylaw (plural bylaws)
- A local custom or law of a settlement or district.
- A rule made by a local authority to regulate its own affairs.
- A law or rule governing the internal affairs of an organization (e.g., corporation or business).
local custom or law
law or rule governing the internal affairs of an organization