Something annoying (8)
I believe the answer is:
nuisance
'something annoying' is the definition.
(I know that nuisance are annoying)
This is the entire clue.
(Other definitions for nuisance that I've seen before include "See 16" , "Trouble" , "Annoying or troublesome person or thing" , "Pest or irritation" , "Pest, source of annoyance" .)