The free online encyclopedia Wikipedia includes a lengthy article on the term “mushing.” After a few introductory lines about alternative meanings of the word comes this definition:
“Mushing is a general term for a sport or transport method powered by dogs, and includes carting, pulka, scootering, sled dog racing, skijoring, freighting, and weight pulling. More specifically, it implies the use of one or more dogs to pull a sled on snow. The term is thought to come from the French word marche, or go, run, the command to the team to commence pulling. ‘Mush!’ is rarely used in modern parlance, however; ‘Hike!’ is more common in English. Mushing can be utilitarian, recreational, or competitive.”
