Temporarily quiet, party talk loudly about first of members (7)
I believe the answer is:
dormant
'temporarily quiet' is the definition.
(I've seen this before)
'party talk loudly about first of members' is the wordplay.
'party' becomes 'do' (do is a kind of party).
'talk loudly' becomes 'rant'.
'about' is an insertion indicator.
'first of members' becomes 'm' (1st letter of 'members').
'rant' going around 'm' is 'rmant'.
'do'+'rmant'='DORMANT'
(Other definitions for dormant that I've seen before include "Suspended" , "In deep sleep" , "Latent" , "Sleeping or inactive, say volcano" , "Mordant about lying inactive" .)