nullify

v.无效

使无效；废除；取消；抵消；抵销；使失去法律效力；使失去实际意义；宣告无效；使作废；撤销；抹去。

动词；

1. The court decision nullified the previous ruling and declared the law unconstitutional.

法院的裁决使之前的判决无效，并宣布该法律违宪。

2. His mistake nullified all his efforts to win the race.

他的错误使他努力争取比赛胜利的一切努力都白费了。