A quarrel, fight, or brawl; can refer to anything from an argument to a physical scuffle (often used as 'to quarrel/fight').
子供たちが遊んでいて喧嘩を始めた。
The children were playing and started fighting.
あの二人は小さなことで喧嘩をしている。
Those two are quarrelling over something small.
近所で夜遅く喧嘩の声が聞こえた。
I heard voices from a quarrel in the neighborhood late at night.
彼らの喧嘩はすぐに仲裁された。
Their fight was quickly mediated.