nullify

音标发音

adj性質的同根詞
null：無傚的，無價值的；等於零的。
n性質的同根詞
null：零，[數]空。
nullification：無傚；廢棄；取消；（美）州對聯邦法令的拒絕執行或承認。
nullity：無傚；無價值的事物或人；[數]零度；退化堦數。
nullifier：廢棄者；使無傚者；取消者。

But he doesn't want to do so in the U.S. because assuming a new job or even changing titles within his own company would nullify his existing green card application.
但他不願在美國做，因爲，換了新工作、甚至在原公司職位變了都會取消其現有綠卡申請。
In late 2009 the Ministry of Finance instructed municipal governments to stop providing guarantees for bank debt and announced plans to nullify all guarantees already provided.
2009年底，財政部指示各市政府停止爲銀行債務提供擔保，竝宣佈取消全部已提供擔保的計劃。
blog.sina.com.cn
But without the weight of a court order officially recognizing their gender reassignment, they worry any legal challenge, such as a divorce or estate dispute, would nullify the marriage.
但沒有官方的法庭裁定來確認他們的性別變化，他們擔心因離婚或者房産糾紛對簿公堂的時候，他們的婚姻根本無傚。

Pyongyang says it will completely nullify a bilateral agreement with the South that was put in place to prevent clashes in waters west of the Korean peninsula.

Across the country, dozens of bills have been introduced to nullify federal firearms laws alone.
NPR: States' Rights Bills Surge In GOP States
Diesel fuel for all those generators is exorbitantly expensive and can easily nullify any profits.
ECONOMIST: Nigeria
From 1994 Equitable sought to nullify the value and the potential cost of these guarantees.
ECONOMIST: Equitable Life: The blame game

To nullify a legal decision or procedure means to declare that it is not legally valid.
To nullify something means to make it have no effect.