Greg Wyshynski at Yahoo Sports has an exhaustive history of the term. The bottom line: It’s not totally clear where it came from, but it’s not considered offensive by the vast majority of Canadians.
Today, Canuck is generally synonymous with Canadian. But it could have started as a combination of “Canada” and “Chinook,” Wyshynski reports. The Chinooks are a large tribe in the Pacific Northwest.
At one time, it may have only referred to French Canadians.
Or it could be derived from “kanaka,” a word to describe a South Sea Islander involved in the fur trade.
Later, Johnny Canuck was the Canadian response to Uncle Sam. In political cartoons, he was portrayed as “an amiable blue-collar lunk-head who stood up to Uncle Sam’s bullying,” Wyshynski reports.
The Vancouver Canucks were born in 1945 as a minor league hockey team. The name was chosen to honor the Canadian soldiers who fought in World War II. The name stuck when the team joined the NHL in 1970.