Removal from office (7)
(Other definitions for deposal that I've seen before include "written testimony" , "degrading" .)
'removal from office' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for dismissal that I've seen before include "removal from office" , "sack" , "Notice" , "brush-off" , "Termination of employment" .)