1.
If there is ~, there is a lot of shouting and noise because people are very angry or upset about something.
The announcement caused ~ in the crowd...
The courtroom was in an ~.
N-UNCOUNT: also a N, oft in N
2.
You can also use ~ to refer to a lot of public criticism and debate about something that has made people angry.
The town is in ~ over the dispute...
The surprise announcement could cause an ~ in the United States.
N-UNCOUNT: also a N