Brook, burn (6)
I believe the answer is:
stream
I believe this clue is a double definition.
'brook' is the first definition.
(I've seen this in another clue)
'burn' is the second definition.
(burn is a Scottish dialect word for a stream)
(Other definitions for stream that I've seen before include "Master (anag) - current" , "pupils pour out" , "Moving water" , "Rill, brook" , "schoolchildren grouped together" .)