官方把它歸零
歸零的動作由法院或官方做出，對象是文件或結果。
verb · C2
To state officially that something such as a contract, a vote or a result has no legal force, so that in law it no longer counts.
宣告無效（法律）
核心畫面
A good picture for this word is a number being set back to zero. Something had force or value a moment ago, and then a stroke of a pen, or a change somewhere else, leaves it at nothing. The word does not say the thing disappeared; the paper is still on the desk and the money is still in the bank. What has gone is the counting: it no longer adds up to anything.
可以想成一個數字被歸零的畫面。前一刻它還有效力、還有價值，下一刻一支筆或一個變動讓它變成零。這個字並沒有說東西不見了…更多收起
可以想成一個數字被歸零的畫面。前一刻它還有效力、還有價值，下一刻一支筆或一個變動讓它變成零。這個字並沒有說東西不見了：合約還在桌上，錢還在帳戶裡。不見的是「它還算不算數」這件事。From the word’s history
The word is null plus -ify, that is, to make something null — to make it zero. The zero in the root is why the word is so total: nullify is not to weaken something, it is to leave it counting for nothing.
這個字是 null 加上 -ify，也就是「使它變成 null」，變成零。字根裡那個「零」，正好解釋了它為什麼那麼徹底：nullify 不是把東西削弱，而是讓它一點都不算數。
Wiktionary etymology in this packet (source_ref kaikki:3f6f69a190036ae4:39660147:28259): From null + -ify.
Two branches
另一股力量把它吃掉
同樣是歸零，但沒有人宣告，是另一邊的力量把這一邊抵銷掉。
verb · C1
To take away the effect, the value or the good result of something, so that it counts for nothing.
抵銷；使失去效果