Crackpot’s proceedings against teachers? (7)
I believe the answer is:
nutcase
'crackpot's' is the definition.
('nutcase' can be a synonym of 'crackpot')
'proceedings against teachers?' is the wordplay.
'proceedings' becomes 'case' (case is a kind of proceedings).
'against' is a charade indicator (letters next to each other).
'teachers?' becomes 'nut' (National Union of Teachers).
'case' put after 'nut' is 'NUTCASE'.
(Other definitions for nutcase that I've seen before include "Maybe almond covering" , "He's mad" , "Maniac - shell" , "Madman (colloq.)" , "One may finish in the madhouse" .)