Caught in exam with electronic medium providing revelation (6)
I believe the answer is:
oracle
'medium providing revelation' is the definition.
(an oracle is a medium for mystical knowledge)
'caught in exam with electronic' is the wordplay.
'caught' becomes 'c' (cricket abbreviation).
'in' is an insertion indicator.
'exam' becomes 'oral' (spoken academic test).
'with' says to put letters next to each other.
'electronic' becomes 'e' (as in e-mail or e-books).
'c' inserted within 'oral' is 'oracl'.
'oracl'+'e'='ORACLE'
(Other definitions for oracle that I've seen before include "Medium of divine revelation" , "Adviser t" , "Infallible indication" , "Ancient Greek expounder of wisdom" , "Source of prophecies" .)