n.

1. 正當的報應
2. 給以報應者；復仇者
3. 必然使計畫失敗的人，勁敵；無可避免的後果
   For the last thirty years, he has been my nemesis.

   在過去三十年來，他一直是我的勁敵。

n.

1. the inescapable agent of someone's downfall, especially when deserved.
   ▸a downfall caused by an inescapable agent.
2. chiefly N. Amer. a long-standing or persistent rival or enemy.