Unimportant person making boy nod off (6)
I believe the answer is:
nobody
'unimportant person' is the definition.
(I've seen this before)
'boy nod off' is the wordplay.
'off' indicates anagramming the letters.
'boy'+'nod'='boynod'
'boynod' with letters rearranged gives 'NOBODY'.
'making' acts as a link.
(Other definitions for nobody that I've seen before include "Pooter as a diarist" , "who can square the circle?" , "Person without influence" , "Person without authority or standing - hardly exists" , "The Diary of a --- (George &Weedon Grossmith)" .)