Used to becoming ejected (6)
I believe the answer is:
ousted
'ejected' is the definition.
(I've seen this in another clue)
'used to becoming' is the wordplay.
'becoming' is an anagram indicator.
'used'+'to'='usedto'
'usedto' with letters rearranged gives 'OUSTED'.
(Other definitions for ousted that I've seen before include "Drove or ejected from office" , "Removed from office (6)" , "Driven out" , "Used to (anag)" , "Offences against the law of the land" .)