Offensive din taking over start of meeting (7)
I believe the answer is:
noisome
'offensive' is the definition.
(I know that offensive can be written as noisome)
'din taking over start of meeting' is the wordplay.
'din' becomes 'noise' (a din is a noisy disturbance).
'taking over' is an insertion indicator (inserted letters are taken over or captured).
'start' says to take the initial letters.
The first letters of 'of meeting' is 'om'.
'noise' going around 'om' is 'NOISOME'.
(Other definitions for noisome that I've seen before include "Unpleasantly smelling" , "Nauseating" , "Offensive, noxious" , "Offensively smelling" , "terribly unpleasant" .)