definition
strict definition
canton
An official territorial division called a canton, with constitutional status and rank set locally.
A canton is an official territorial division in a country whose law or established terminology uses that name.
Swiss cantons are constituent members of a federation, each with its own government and laws. French cantons are electoral divisions that usually group municipalities. Other countries give the term still different powers and positions.
The word therefore does not establish a fixed tier or degree of self-government. Its common feature is the official designation of a defined territorial unit.