Master different flow (6)
I believe the answer is:
stream
'flow' is the definition.
(stream is a kind of flow)
'master different' is the wordplay.
'different' indicates anagramming the letters.
'master' anagrammed gives 'STREAM'.
(Other definitions for stream that I've seen before include "Small narrow flow" , "Master (anag) - current" , "River - current" , "schoolchildren grouped together" , "Current - file" .)