"Canuck" is a slang term for "Canadian" in Canadian English and sometimes in American English
The term was coined in the 19th century, although its etymology is unclear. Possibilities include:
The Random House Dictionary notes that: "The term Canuck is first recorded about 1835 as an Americanism, originally referring specifically to a French Canadian. This was probably the original meaning, though in Canada and other countries, Canuck now more often refers to any Canadian." *
The use of "Canuck" by Canadians themselves is usually affectionate or patriotic.
The history and use of the term include:
The use of "Canuck" parallels that of some other potentially offensive nicknames, that is, when used by the people it names — Canadians in this case — it is usually acceptable. But when used by an outsider — in this case particularly American strangers — it can be easily misinterpreted and deemed as insulting one's heritage. Although it is not as severe as most ethnic slurs, some consider it one.