Unimportant person (6)
I believe the answer is:
nobody
'unimportant person' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for nobody that I've seen before include "Person without influence" , "Pooter as a diarist" , "not a VIP" , "Not a soul" , "Submissiveness, gentleness" .)