to·bog·gan

n.           A long, narrow, runnerless sled constructed of thin boards curled upward at the front end. [Corruption of American Indian odabagan a sled.] A kind of sledge made of pliable board, turned up at one or both ends, used for coasting down hills or prepared
inclined planes; also, a sleigh or sledge, to be drawn by dogs, or by hand, over soft and deep snow.
[Written also tobogan, and tarbogan.]

intr.v.    to·bog·ganed, to·bog·gan·ing, to·bog·gans

1. To coast, ride, or travel on a toboggan.
2. Slang. To decline or fall rapidly: His good fortune has tobogganed.