Other forms: peacekeepers
The noun peacekeeper means exactly what it sounds like: a person who tries to keep things peaceful, often by mediating conflicts or calming people down.
You are a peacekeeper if you're the diplomat in your family, the one who negotiates between feuding siblings or placates a cranky grandfather to ensure that everyone has a pleasant Thanksgiving dinner. The most common way to use the word peacekeeper, however, is to talk about troops that are sent into another country for non-military purposes. For example, the United Nations often uses peacekeepers to calm tensions within countries in danger of civil war or violent uprisings.