Toboggan

czapka

(knit cap)

tobogan

(long sled without runners)

tobogan

(sled pulled by dogs, with runners)

zapaść

(figuratively: something that slides downhill uncontrolled)

jeździć na toboganie

(to slide down a hill with a toboggan or similar)

zapadać się

(figuratively: to go downhill unstoppably)

zapaść się

(figuratively: to go downhill unstoppably)