The Collaborative International Dictionary of English v.0.48:

Toboggan \To*bog"gan\, v. i. [imp. & p. p. Tobogganed; p. pr.
   & vb. n. Tobogganing.]
   To slide down hill over the snow or ice on a toboggan.
   --Barilett.
   [1913 Webster] Tobogganer

WordNet (r) 3.0 (2006):

tobogganing
    n 1: riding on a long light sled with low handrails