Definitions

illegal

[ih-lee-guhl] / ɪˈli gəl /

ADJECTIVE

against the law

Synonyms

STRONGEST

banned criminal illegitimate illicit irregular outlawed prohibited smuggled unauthorized unconstitutional unlawful unlicensed unwarranted wrongful

WEAK

actionable black-market bootleg contraband crooked extralegal felonious forbidden heavy hot interdicted lawless not approved not legal outside the law proscribed prosecutable racket shady sub-rosa taboo under-the-table unofficial unwarrantable verboten violating wildcat

Antonyms

STRONGEST

authorized blessed ethical good justifiable lawful legal legitimate moral permitted right warranted

WEAK

allowed permissible

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Illegal cattle ranching has already destroyed millions of acres.

From Science Daily • Nov. 22, 2025

Illegal border crossings have slowed to a near-halt, and the labor-participation rate among foreign-born workers continues to fall.

From Barron's • Oct. 9, 2025

Illegal migration includes people who arrive on small boats, or hidden in lorries, and people who remain in the UK after their legal visa expires.

From BBC • May 21, 2025

Illegal border crossings have plummeted over the last few months, federal data show.

From Los Angeles Times • Apr. 30, 2025

After weeks of hearing testimony concerning the raids, the committee issued what it titled “A Report on the Illegal Practices of the United States Department of Justice.”

From "1919 The Year That Changed America" by Martin W. Sandler

Vocabulary lists containing illegal

List 3

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"A Natural Balance" and "In My Dreams"

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Fear and Loathing in Cleveland: Trump's RNC Acceptance Speech

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