Cohort of pupils stumped by some paper (6)
I believe the answer is:
stream
'cohort of pupils' is the definition.
'stream' can be an answer for 'pupils' (stream can mean a class of similarly able pupils). I am not certain of the 'cohort of' bit.
'stumped by some paper' is the wordplay.
'stumped' becomes 'st' (cricket abbreviation).
'by' says to put letters next to each other.
'some paper' becomes 'ream' (I've seen this before).
'st'+'ream'='STREAM'
Can you help me to learn more?
(Other definitions for stream that I've seen before include "'Current, flow (6)'" , "Constant flow of liquid" , "selected pupils" , "course" , "Rill, brook" .)