Musher's transport (4)
I believe the answer is:
sled
'musher's transport' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for sled that I've seen before include "Toboggan (mainly US)" , "Sledge" , "Sleigh" , "American toboggan" , "Tray on which to slide" .)