Job? No, it is work to be rebuffed (8)
I believe the answer is:
position
'job?' is the definition.
(position is a kind of job)
'no it is work to be rebuffed' is the wordplay.
'it is' becomes 'itis'.
'work' becomes 'op' (abbreviation for opus).
'to be rebuffed' shows that the letters should be reversed in order.
'no'+'itis'+'op'='noitisop'
'noitisop' written backwards gives 'POSITION'.
(Other definitions for position that I've seen before include "Set in place" , "Place - situation" , "Put" , "Place where something is" , "Job; point of view" .)