Burn the new master (6)
I believe the answer is:
stream
'burn' is the definition.
(burn is a Scottish dialect word for a stream)
'new master' is the wordplay.
'new' is an anagram indicator.
'master' is an anagram of 'STREAM'.
'the' is the link.
(Other definitions for stream that I've seen before include "Running liquid" , "Brook or small river" , "Master (anag) - current" , "Flowing water" , "Constant flow of liquid" .)