Unimportant person (6)
'unimportant person' is the definition.
(I've seen this before)
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" .)
(Other definitions for small fry that I've seen before include "Tiddlers - trifling things" , "Little fish - trivial things" , "Minor" , "Unimportant people like tiny fish" , "Unimportant things - minnows?" .)