The idiom "up in arms" means to be very angry or upset about something and to express your strong opposition to it. It can also refer to a situation where people are ready to fight or take action against something they strongly disagree with.
For example, if a group of people found out that their local park was going to be turned into a parking lot, they might be up in arms about it. They would be very angry and upset about the decision and would likely protest or take other actions to try to stop it from happening.
You can use this idiom in a variety of situations where people are angry or upset about something. It is often used in news headlines or in discussions about controversial issues. It is important to note that this idiom is informal and should be used in casual conversations or writing, rather than in formal or academic contexts.
• My mom was up in arms when she found out I had skipped school.
• The activists were up in arms over the environmental destruction caused by the oil company.
• The employees were up in arms over the new company policy.
• The citizens were up in arms about the government's decision to raise taxes.
• The international community was up in arms about the human rights violations in the country.
• The neighbors were up in arms about the noise from the construction site.