Winter transport, we hear, for butcher (4)
I believe the answer is:
slay
'butcher' is the definition.
(both can mean to murder)
'winter transport we hear' is the wordplay.
'winter transport' becomes 'sleigh' (I've seen this before).
'we hear' shows a homophone (sound like).
'sleigh' is a homophone of 'SLAY'.
'for' acts as a link.
(Other definitions for slay that I've seen before include "Kill (literary)" , "Butcher" , "Destroy" , "Violently kill" , "Fatally hit" .)