Charge with treason (7)
I believe the answer is:
impeach
'charge with treason' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for impeach that I've seen before include "Charge public official with misconduct - Clinton?" , "Charge with major crime" , "Bring a charge against" , "Criticise" , "Level a charge against -- pace him (anag)" .)