An interfering person (8)
I believe the answer is:
busybody
'an interfering person' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for busybody that I've seen before include "One minds everyone else's business" , "A meddlesome person, certainly not idle" , "butter in" , "One meddling" , "Prying person" .)