1
leave sth unchecked
leave + 宾语 + unchecked 表示“放任不管”，常见被动形式 be left unchecked。
If left unchecked, the fire could spread to the whole forest.
如果不加控制，火势可能会蔓延到整片森林。
不受约束的；未加抑制的
先理解核心含义，再看它在真实句子里的用法。
不受约束的；未加抑制的
not restrained or controlled
If left unchecked, the fire could spread to the whole forest.
如果不加控制，火势可能会蔓延到整片森林。
不受约束的,未受抑制的
Unrestrained, not held back.
未经检查准确性或效率等的
Not examined for accuracy, efficiency, etc.
复选框未勾选的(未选中或未启用)
Of a check box: not checked (ticked or enabled).
仅属于一个词条(横向或纵向,但不是两者)的方格
Of a square: part of only one entry (that is, across or down, but not both).
The fire spread unchecked through the dry forest, destroying everything in its path.
大火在干燥的森林中不受控制地蔓延，摧毁了沿途的一切。
If corruption goes unchecked, public trust in the government will continue to fall.
如果腐败得不到遏制，公众对政府的信任将继续下降。
The company's unchecked spending led to serious financial problems within two years.
公司不加节制的开支在两年内导致了严重的财务问题。
leave + 宾语 + unchecked 表示“放任不管”，常见被动形式 be left unchecked。
If left unchecked, the fire could spread to the whole forest.
如果不加控制，火势可能会蔓延到整片森林。
remain 作系动词，后接形容词 unchecked，表示“持续处于未受控制的状态”。
The disease remained unchecked for months because of a lack of medicine.
由于缺乏药物，这种疾病数月来一直未受控制。
unchecked 作定语修饰名词，可译为“不加约束的”“未受抑制的”。
Unchecked spending led the company into debt.
不加节制的开支使公司陷入债务。
Not this
The spread of the disease was uncheck by the government.
Use this
The spread of the disease was unchecked by the government.
be 动词后需要用形容词（或过去分词形式）unchecked 作表语，表示“未受抑制的”；uncheck 是动词原形，意思是“取消勾选”，不能表达“未加控制”。只有加上 -ed 变成 unchecked 才能与 be 构成正确的系表结构。
Not this
The disease spread uncheckedly across the country.
Use this
The disease spread unchecked across the country.
spread 在这里是不及物动词，unchecked 是说明主语状态的形容词补足语，意为“未受控制的”；英语的习惯搭配是 spread unchecked，不需要用副词 uncheckedly 来修饰动词。因此应把 -ly 去掉，保留形容词形式。
Focus on the distinctions below. Other candidates are kept compact until a reliable usage note is available.
不受控制的增长
The unchecked growth of the city has led to serious traffic problems.
城市不受控制的增长导致了严重的交通问题。
不受约束的权力
No democratic system should allow unchecked power in one branch of government.
任何民主制度都不应允许政府的一个部门拥有不受约束的权力。
毫无节制的野心
His unchecked ambition eventually destroyed his career.
他毫无节制的野心最终毁掉了他的事业。
无节制的蔓延
The unchecked spread of the virus is a global concern.
病毒的肆意蔓延是一个全球性的担忧。
不受限制地发展/蔓延
Poverty and disease run unchecked in the war-torn region.
在这个饱受战争蹂躏的地区，贫困和疾病肆虐横行。
不受遏制；任其发展
If this trend goes unchecked, the damage will be irreversible.
如果这种趋势不受遏制，破坏将不可逆转。
（尤指坏事）蔓延失控
Without strict rules, corruption can run unchecked.
没有严格的规则，腐败就会蔓延失控。
不加约束；放任不管
The problem was left unchecked for too long.
这个问题被放任不管太久了。
Use unchecked naturally, then get feedback on meaning, tone, grammar, and phrasing.
Revisit a common error or keep this word in your review list.
unchecked = 没被check住，所以不受控制；像没打勾的选项，放任不管。
语域：neutral 常见场景：news reports、policy discussions、academic writing 该义项多用于正式或较中性的语境，表示问题、风险或不良现象没有被制止或控制，比较常见于新闻报道、政策讨论和学术文本。日常口语中较少单独使用；另外注意它也可在计算机语境中表示“未选中的”，两者需根据上下文区分。
Words ending with /ɛkt/ (checked, wrecked, decked, respect, expect, collect) rhyme with unchecked. But beware of lookalikes such as 'uncheck' /ʌnˈtʃɛk/ and 'cheque' (BrE) /tʃɛk/, which lack the final /t/ and have different meanings.
Dictionary facts from ECDICT, WIKTIONARY.