Break his leg with a toboggan (6)
I believe the answer is:
sleigh
'a toboggan' is the definition.
(I know this)
'break his leg' is the wordplay.
'break' indicates an anagram.
'his'+'leg'='hisleg'
'hisleg' with letters rearranged gives 'SLEIGH'.
'with' is the link.
(Other definitions for sleigh that I've seen before include "Reindeer-pulled sledge" , "Toboggan" , "Carriage to run on snow" , "13 ac's transport" , "vehicle drawn by reindeer" .)