A dramatic action on skis or a snowboard in which the rider crashes and turns end-over-end four consecutive times for a 1440 degree spin. This gives them the appearence of a spinning Tomahawk, hence the name.
Featured in Warren Miller's "Playground", a ski-enthusiast movie.
Skier: "Oh man, look at that guy swerving."
Snowboarder: "Yup, he's going down."
Skier: "Wait for it...wait for it...OH! Down he goes!"
Snowboarder: "One, two, three..."
Skier: "Hell yeah! That's four turns!"
Snowboarder: "Tomahawk 1440, bitches!"
Skier: "He's gonna be feeling that for a good week!"