Devilish fifth grade male disrupts teacher in charge (7)
I believe the answer is:
demonic
'devilish' is the definition.
(I've seen this before)
'teacher in charge' is the wordplay.
'teacher' becomes 'demon' (I can't justify this - if you can you should believe this answer much more).
'in charge' becomes 'ic' (abbreviation for 'in charge').
'demon'+'ic'='DEMONIC'
'fifth grade male disrupts' acts as a link.
This may not be correct. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for demonic that I've seen before include "Furious" , "Cruel like the devil" , "Fiendish or satanic" , "Dime con (anag.)" , "Wicked" .)