Celeb briefly backed into corrupt poll (8)
I believe the answer is:
election
'poll' is the definition.
(I've seen this before)
'celeb briefly backed into corrupt' is the wordplay.
'briefly' means to remove the last letter.
'backed' says the letters should be written in reverse.
'corrupt' indicates an anagram.
'celeb' with its final letter taken off is 'cele'.
'cele' written backwards gives 'elec'.
'into' with letters rearranged gives 'tion'.
'elec'+'tion'='ELECTION'
(Other definitions for election that I've seen before include "Formal vote" , "An act of democracy" , "When MPs are chosen" , "Selection by ballot" , "Procedure for choosing government" .)