The Random House Dictionary notes that: "The term Canuck is first recorded about 1835 as an Americanism (American term), originally referring specifically to a French Canadian. This was probably the original meaning, though in Canada and other countries, "Canuck" refers to any Canadian."  For example, someone residing in Toronto might be considered a "Canuck". In fact, the 1835 source cited refers to a foreign-speaker: "Jonathan distinguishes a Dutch or a French Canadian, by the term Kanuk". Although its etymology is unclear, possible origins include:
Genna, an obscure term for Irish-French-Canadians.
In Cree Indian mythology, there existed a wolf-spirit called "Kannuk". This may be a possible origin for the term/ name "Canuck"...an Anglicization of the aboriginal word "Kannuk".
Usage and examples
Canadians use "Canuck" as an affectionate or merely descriptive term for their nationality. It is not considered derogatory in Canada, although other nationalities may use the word as an affectionate or derogatory term. An abbreviated version of the word, "Nucks", is sometimes heard, usually as a colloquial reference to the hockey team.
"Canuck" is a nickname for the Curtiss JN4biplane and Avro CF-100jetfighter. The CF-100 was the only Canadian-designed and built jet fighter to enter operational service. From 1950–1958, 692 Canucks were built. They remained in service until 1981.
One of the first uses of "Canuck" — in the form of "Kanuk" — specifically referred to Dutch Canadians as well as the French.
The Crazy Canucks, Canadian alpine ski racers who competed successfully on the World Cup circuit in the '70s.
Johnny Canuck, a personification of Canada who appeared in early political cartoons of the 1860s resisting Uncle Sam's bullying. Johnny Canuck was revived in 1942 by Leo Bachle to defend Canada against the Nazis. The Vancouver Canucks have adopted a personification of Johnny Canuck on their alternate hockey sweater. The goaltender for the Canucks Roberto Luongo, has a picture of Johnny Canuck on his goalie mask.
In 1975 in comics by Richard Comely, Captain Canuck is a super-agent for Canadians' security, with Redcoat and Kebec being his sidekicks. (Kebec is claimed to be unrelated to Capitaine Kébec of a French-Canadian comic published two years earlier.) Captain Canuck had enhanced strength and endurance thanks to being bathed in alien rays during a camping trip. The captain was reintroduced in the mid-1990s, and again in 2004.
Operation Canuck was the designated name of a British SAS raid led by a Canadian captain, Buck McDonald in January 1945.
"Canuck" also has the derived meanings of a Canadian pony (rare) and a French-Canadian patois (very rare).
The Canuck letter became a focal point during the US 1972 Democratic primaries, when a letter published in the Manchester Union Leader implied Democratic contender Senator Edmund Muskie was prejudiced against French-Canadians. Soon, as a result, he ended his campaign. The letter was later discovered to have been written by the Nixon campaign in an attempt to sabotage Muskie.
The Marvel Comics character Wolverine is often referred to affectionately as "the Ol' Canuklehead" due to his Canadian heritage.
In the novel Infinite Jest, by David Foster Wallace, French-Canadians are often referred to as "'Nucks."