Banish not entirely fair English Liberal (5)
I believe the answer is:
expel
'banish' is the definition.
(I know that banish is a more specific form of expel)
'not entirely fair english liberal' is the wordplay.
'not entirely' means to remove the last letter (not all of the word).
'fair' becomes 'expo' (an expo is a type of large exhibition).
'english' becomes 'E' (abbreviation).
'liberal' becomes 'l' (abbreviation).
'expo' with its last letter removed is 'exp'.
'exp'+'e'+'l'='EXPEL'
(Other definitions for expel that I've seen before include "Discharge in disgrace" , "Get rid" , "Oust" , "Eject (from school)" , "Evict" .)