also run-off, "precipitation water drained by streams and rivers," 1887, from run (v.) + off (adv.). Meaning "deciding race after a tie" is from 1873; electoral sense is attested by 1910, American English.
权威例句
1. The streams are flush with the spring runoff.
溪涧涨满春水.
2. The sewers collected sewage and storm runoff and discharged it, untreated, into the harbour.
污水和暴雨径流汇入下水道后被直接排入海港。
3. In the east, the water is mainly oceanic with relatively minor dilution from direct monsoonal rainfall and runoff from small streams.
东部水域主要为海水,而直接的季候雨及小溪溢流,把海水稍为冲淡.
4. Another municipal waste problem is street runoff into storm sewers.
有关都市废水的另外一个问题是进入雨水沟的街道雨水.
5. Aerial photography can provide valuable information on precipitation, evapotraspiration, interception, and runoff.