Fellow venturing to unseat last bureaucrat (8)
I believe the answer is:
mandarin
'bureaucrat' is the definition.
(I've seen this before)
'fellow venturing to unseat last' is the wordplay.
'fellow' becomes 'man' (I've seen this before).
'venturing' becomes 'daring'.
'to unseat last' means to remove the last letter (the last letter is ousted or unseated).
'daring' with its final letter taken off is 'darin'.
'man'+'darin'='MANDARIN'
(Other definitions for mandarin that I've seen before include "Asiatic duck" , "Form of Chinese" , "Small orange-like fruit (from China?)" , "Reddish-orange, loose-skinned citrus fruit" , "Chinese language; fruit" .)