Discordant noises after start of Society meeting (7)
I believe the answer is:
session
'meeting' is the definition.
(session is a kind of meeting)
'discordant noises after start of society' is the wordplay.
'discordant' indicates anagramming the letters.
'after' means one lot of letters go next to another.
'start of' says to take the initial letters.
The initial letter of 'society' is 's'.
'noises' anagrammed gives 'ession'.
'ession' after 's' is 'SESSION'.
(Other definitions for session that I've seen before include "Court sitting" , "Period of business for official body" , "Period spent on a single activity" , "Meeting of a court or parliament" , "Time in legislature" .)