Fellow with the cheek to oust last bureaucrat (8)
I believe the answer is:
mandarin
'bureaucrat' is the definition.
(I know that bureaucrat can be written as mandarin)
'fellow with the cheek to oust last' is the wordplay.
'fellow with' becomes 'man' (I've seen this in other clues).
'the cheek' becomes 'daring' (cheek can mean daring or audacity).
'to oust last' means to remove the last letter.
'daring' with its last letter taken away is 'darin'.
'man'+'darin'='MANDARIN'
(Other definitions for mandarin that I've seen before include "Language formerly used by educated Chinese, or a kind of orange" , "High-ranking bureaucrat" , "Variety of citrus fruit" , "Top civil servant" , "High-ranking official or small orange" .)