A knit cap, designed to provide warmth in cold weather.
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.
Something which, once it starts going (figuratively) downhill, is unstoppable until it reaches the bottom.
A similar sled of wood, pulled by dogs, possibly with steel runners, made to transport cargo.
To go downhill unstoppably until one reaches the bottom.
To slide down a hill on a toboggan or other object.
To fly sharply downward so as to build up speed to facilitate in-flight refueling of a faster aircraft.
A watch cap.