Students turn up with beer (6)
I believe the answer is:
pupils
'students' is the definition.
('pupil' can be a synonym of 'student')
'turn up with beer' is the wordplay.
'turn' is a reversal indicator.
'with' is a charade indicator (letters next to each other).
'beer' becomes 'pils'.
'up' written backwards gives 'pu'.
'pu'+'pils'='PUPILS'
(Other definitions for pupils that I've seen before include "The charges" , "Schoolkids" , "Students' eye parts" , "Schoolchildren" , "Scholastics in the eye" .)