n. A long sled without runners, with the front end curled upwards, which may be pulled across snow by a cord or used to coast down hills.n. A similar sled of wood, pulled by dogs, possibly with steel runners, made to transport cargo.n. a winter hat or ski maskn. Something which, once it starts going (figuratively) downhill, is unstoppable until it reaches the bottom.v. to slide down a hill on a toboggan or other objectv. to (figuratively) go downhill unstoppably until one reaches the bottom.