peacekeeper

noun

1. One that preserves the peace.

   “Roughly 1200 years ago, the turians were invited to join the Citadel Council to fulfill the role of galactic peacekeepers. The turians have the largest fleet in Citadel space, and they make up the single largest portion of the Council's military forces.”

2. A member of a military force charged with peacekeeping duties in a troublespot.

   “The grainy footage showed the peacekeepers first bound and beaten, then hooded and dead, hanging by the neck from a wooden ceiling beam. .”

   “Dozens of NATO peacekeepers were injured after they were attacked by ethnic Serbs in northern Kosovo, during protests over the installation of ethnically Albanian mayors.”

3. (Canada)An officer of the peace (police officer) in a force run by a Canadian aboriginal community.