Driven out (6)
'driven out' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for ousted that I've seen before include "Removed from office (6)" , "Put or thrust out" , "Put forcibly out of office" , "Forcibly ejected from office or position" , "Booted out of office" .)
(Other definitions for displaced that I've seen before include "Forced to leave home" , "Moved from its proper position" , "Supplanted" .)