adjective
1. having or showing an eagerness to fight; aggressive; warlike.
More guards were called when the prisoner became belligerent.
He was expelled from school after he became belligerent toward one of his teachers.
2. pertaining to war or to people or countries at war.
The belligerent nations could not be brought to the negotiating table.
noun
1. one who behaves in a belligerent manner.
The belligerents were expelled from school.
2. a person, state, or nation engaged in war.
The belligerents met to draw up a truce.