The stick broke in two. 棍子断成两段。
The string broke. 绳子断了。
cut off the enemy's retreat; 断敌退路
cut off the water supply; 断水
give up smoking; quit [stop] smoking 断烟
decide promptly and opportunely; make a prompt decision; 当机立断
diagnose 诊断
absolutely incredible; 断不可信
absolutely untenable [unreasonable]; the height of absurdity 断无此理
Duan Nan 断南
牛津高阶第八版
美国韦氏词典
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维基百科 (自由的百科全书)