runoff，英语单词，主要用作名词、形容词，作名词时译为“[水文] 径流；决赛；流走的东西”，作形容词时译为“决胜的”。

柯林斯英汉双解大词典

runoff /ˈrʌnɔːf/ ( runoffs )

1.N-COUNT A runoff is an extra vote or contest which is held in order to decide the winner of an election or competition, because no one has yet clearly won. 决选; 决胜赛 [usu sing, oft N 'between' pl-n]

surface runoff[水文] 地表径流 ; 地面迳流 ; 地表径流量 ; 表面径流

urban runoff 城市径流

runoff coefficient 流系数 ; 经恋数

runoff generation[水文] 产流

river runoff 河川径流 ; 径流量 ; 河流径流量

presidential runoff 总统决胜选举

runoff cycle[水文] 径流循环 ; 迳流循环

runoff change 径流变化