An indexing radical for combat and contest. Compounds are mostly archaic: 鬧 (to make a row, simplified 闹), 鬨 (uproar), 鬩 (squabble), 鬪 / 鬬 (variant fight forms). After simplification merged the productive 鬥 family into 斗, the radical's role in mainland dictionaries shrank — but it remains canonical in Kangxi numbering.