Sounds upset over special meeting (7)
I believe the answer is:
session
'meeting' is the definition.
(session is a kind of meeting)
'sounds upset over special' is the wordplay.
'sounds' becomes 'noises' (noising is a kind of sounding).
'upset' shows that the letters should be reversed in order.
'over' indicates putting letters inside.
'special' becomes 's' (common abbreviation as in Special Air Service).
'noises' backwards is 'sesion'.
'sesion' placed around 's' is 'SESSION'.
(Other definitions for session that I've seen before include "Period of business for official body" , "School term" , "Meeting devoted to a particular purpose" , "Meeting of a court or parliament" , "Meeting, sitting, term" .)