Current group in school (6)
I believe the answer is:
stream
I believe this is a double definition.
'current' is the first definition.
(I know that current can be written as stream)
'group in school' is the second definition.
(Other definitions for stream that I've seen before include "group of schoolchildren" , "Small narrow river" , "Flow from master" , "Torrent" , "Flow of water on land" .)