Prying person occupied with main part (8)
I believe the answer is:
'prying person' is the definition.
(I've seen this before)
'occupied with main part' is the wordplay.
'occupied' becomes 'busy' ('busy' can be similar in meaning to 'occupied').
'with' says to put letters next to each other.
'main part' becomes 'body' (I've seen this before).
(Other definitions for busybody that I've seen before include "Meddlesome type" , "One minds everyone else's business" , "butter in" , "Meddling person" , "One meddling" .)