it means to take a Stanley cup filled with the shit of Ryan Reynolds and Avril Lavigne lubricated with Maple Syrup inside the vaginal area of a transgender, while inserting the ends of a moose's antlers into the rectum's of both the transgender and the other person.
Ironically the first known usage of this sexual act occurred as soon as The Beaver changed its name to Canada's History by Stephen Colbert and 72 transgender virgins of unknown origin.
The addition of canadian animals into the sexual act itself is optional.
Damn, did you see what Toby did to that transgender? He totally Canada's Historyed the shit out of it!