Uproar or unusual calm associated with us (7)
I believe the answer is:
clamour
'uproar' is the definition.
(I've seen this before)
'unusual calm associated with us' is the wordplay.
'unusual' indicates anagramming the letters.
'associated with us' becomes 'our' ('our' is the possessive pronoun for 'us').
'calm' with letters rearranged gives 'clam'.
'clam'+'our'='CLAMOUR'
'or' acts as a link.
(Other definitions for clamour that I've seen before include "racket" , "Loud and persistent outcry" , "Loud noise of shouting" , "Hue and cry" , "Loud confused noise" .)