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.

Police departments are also trying to educate the public before issuing citations or towing an illegal bike, but officials said it’s a challenge.

From Los Angeles Times • Jun. 10, 2026

Despite the risks, the flow of illegal migrants from Iraqi Kurdistan to Europe has not stopped, according to Hemn Merany, a senior official at the Kurdistan Regional Government's Ministry of the Interior.

From BBC • Jun. 9, 2026

What’s Next: Kalshi and Polymarket are thriving in states like Texas and California, where traditional sports betting remains illegal, and prediction markets will be the only legal game in town for local bettors.

From Barron's • Jun. 8, 2026

In written testimony, Glynn shared his experience hearing about young women performing illegal abortions when he was a freshman at the University of South Dakota in 1966.

From Salon • Jun. 8, 2026

Like the Frivolous Use Initiative, which made things like throwing water balloons illegal.

From "Dry" by Neal Shusterman and Jarrod Shusterman

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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