Belligerent
/bəˈlɪdʒ.ər.ənt/ adjective easyOpenly hostile and eager to fight or argue.
The referee ejected the belligerent coach after he screamed insults at the officials for the third time.
Memory Trick
'Belli-' comes from the Latin word for war, the same root found in 'antebellum' — a belligerent person is basically spoiling for a fight.