Olympic sled (4)
I believe the answer is:
luge
'olympic sled' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for luge that I've seen before include "Toboggan used in the Winter Olympics" , "Winter sport" , "Racing sled for one or two people" , "Glue for a one-man sledge" , "Olympics sledge" .)