IPA: //bəˈlɪdʒərənt//
KK: /bɪˈlɛdʒərənt/
Having a tendency to be aggressive or ready to fight; showing hostility or combativeness.
The belligerent dog barked loudly at anyone who approached its territory.
A person or group that is aggressive or hostile, especially one involved in conflict or war.
The belligerent nations refused to negotiate a peace treaty.
Belligerent is formed from "bellum" (meaning war) and "-gerent" (from "gerere", meaning to carry or to wage). The word describes someone who is waging war or is inclined to fight.
Think of 'war' ('bellum') being 'waged' ('gerere') by someone — that's why belligerent means someone who is aggressive or ready to fight.