Academic agitatedly cautioned a pupil (11)
I believe the answer is:
educational
'academic' is the definition.
(thesaurus)
'agitatedly cautioned a pupil' is the wordplay.
'agitatedly' is an anagram indicator (I've seen this in other clues).
'pupil' becomes 'l'.
'cautioned' is an anagram of 'education'.
'education'+'a'+'l'='EDUCATIONAL'
(Other definitions for educational that I've seen before include "Providing knowledge" , "Relating to teaching" , "as an aid to learning" , "A docile aunt (anag) - instructive" , "Academic" .)