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.

Elsewhere, Coinbase appeared to shrug off news Tuesday that New York Attorney General Letitia James sued the company for illegal gambling operations on its prediction market platforms.

From Barron's • Apr. 22, 2026

Producing rare earths requires heavy chemicals and can produce toxic waste, with cases including illegal operations polluting Mekong tributaries in Myanmar, Laos and Cambodia with arsenic and cadmium.

From Barron's • Apr. 22, 2026

Placement agencies will also no longer be allowed to implement wage deductions, and it will be illegal to hire children under the age of 18 as domestic workers.

From BBC • Apr. 21, 2026

If the person being sued is a government official, most commonly a cop, then they could only be liable if it was obvious that the cop’s action was illegal.

From Slate • Apr. 21, 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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