illegal
Noun pluralillegals
Pluralillegals
- 1Against the law, or forbidden or not authorized by it.
The company faced heavy fines for its illegal dumping of waste.
Bribing a public official is illegal in nearly every country.
UsageOften it is illegal to + verb: it is illegal to park here; also before activities: illegal dumping.
Note
John Selden's Table-Talk, first published in 1689, already has princes doing "something illegal to get Money." The word came through French illégal from Medieval Latin illegalis, il- plus legal. It often appears in the pattern it is illegal to do something, or before an activity, as in illegal dumping or illegal mining.
- 2Living or residing in a country without legal authorization; applied to a person, and now widely regarded as offensive.
Thousands of illegal residents live in fear of being sent back.
Her parents were illegal when they first arrived in the United States.
UsageMany people find it hurtful when applied to a person; neutral alternatives include undocumented or living in the country without legal permission.
Similarundocumented, unauthorized
Oppositelegal
Note
The immigration sense came from shortening illegal alien or illegal immigrant, and it is chiefly American. Applied to a person, it is now widely regarded as offensive, and many people find it hurtful. Neutral wording such as undocumented avoids the problem. The same clipping produced the noun for a person.
- 3Describing something, such as a move in a game or sport, that the established rules of a game, organization, or activity do not allow.
The boxer was disqualified for an illegal punch below the belt.
The referee ruled the tackle illegal because the player led with his helmet.
UsageCommon in sports and games: an illegal move, an illegal tackle, a play ruled illegal.
Similarprohibited, forbidden, banned
Oppositelegal, permitted, allowed, fair
Note
Here the authority is a rulebook, not a statute. An illegal move in chess breaks no law, and a program that performs an illegal operation has only done something its system forbids. The consequences belong to the rules too: a disqualification, a lost game, a terminated program. When context could mislead, keep it apart from the law-related sense. An illegal punch is a foul, though it may also be a crime.
- 4A person residing in a country without legal authorization; a label many regard as offensive and dehumanizing.
An illegal who has worked here for years still risks sudden deportation.
The sweep detained more than forty illegals in a single night.
UsageMost often used with hostility; neutral writing describes the person's status in full instead.
Note
Turning the adjective into a noun finishes the clipping described under the immigration adjective, and it is the form most often used with hostility. Josh Halliday and Neha Gohil's 2024 report on protests in England quotes a placard reading "no apartments for illegals."
Less common meanings
- 5Contraband, especially banned substances such as drugs.
Similarcontraband, drugs, narcotics
Note
Used in the plural, as a casual catch-all for forbidden goods carried in a pocket or a bag. It belongs to the talk of crime and its fringes: Mason uses it in a 2003 episode of Dead Like Me, and it turns up in J. D. Robb's Strangers in Death (2008). The plural form is shared with the noun for immigrants, so context has to do the work.
Checked 6 Nov 2026 · 4 facts
- Mason uses 'illegals' in Dead Like Me. en.wikiquote.org
- The episode containing Mason's line, 'Reapercussions', first aired in 2003. en.wikipedia.org
- The word occurs in J. D. Robb's Strangers in Death. en.wiktionary.org
- Strangers in Death was first published in 2008. jdrobb.com
- 6A spy operating in a foreign country under non-official cover, without visible ties to their home government's authorities.
An illegal carries no diplomatic protection if caught by the host country.
The agency planted illegals in cities across the rival nation.
Note
Intelligence jargon separates officers under official cover from illegals, who live abroad as ordinary civilians. Shaun Walker, writing in 2022, notes that illegals have traditionally been extremely hard for counterintelligence to find. He adds that biometric data and facial recognition now make the cover harder for Russia to keep. Christopher Andrew (2012) singles out Anna Chapman, caught by a US sting, as the most publicized of them.
Checked 6 Nov 2026 · 6 facts
- Intelligence services distinguish official cover from illegals operating as civilians. mi5.gov.uk
- Walker wrote the cited article in 2022. theguardian.com
- Walker says illegals were traditionally very difficult for counterintelligence to find. theguardian.com
- Walker says biometric data and facial recognition make maintaining Russian illegals' cover harder. theguardian.com
- Christopher Andrew's cited review appeared in 2012. literaryreview.co.uk
- Andrew describes Chapman as receiving more publicity than the other illegals combined and being deceived by a US sting. en.wiktionary.org
- 7An act or technique that is against the law or the rules.
That whatſoever illegals hath been uſed againſt his friends and ſubjects, by impriſoning them without law, or impoſing fines upon their eſtates, be diſclaimed, and that perſons ſo committed be forthwith diſcharged.
c. 1650, John Spalding, The History of the Troubles and Memorable Transactions in ScotlandNote
A noun from the seventeenth century that has since fallen out of use. John Spalding's History of the Troubles in Scotland demands that "whatsoever illegals" used against the king's friends be disclaimed, meaning imprisonment without law and fines on estates.
- 8In stamp collecting, of a stamp or other issue: printed without the authorization of any genuine postal authority, usually in the name of an existing country or territory.
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Origin
Borrowed from French illégal, from Medieval Latin illegalis, ultimately from Latin legalis, and analyzable as il- + legal. In immigration senses, it comes from a shortening of illegal alien or illegal immigrant.
Checked 6 Nov 2026 · 5 facts
- English illegal was borrowed from French illégal. en.wiktionary.org
- French illégal derives from Medieval Latin illegalis. en.wiktionary.org
- The word ultimately derives from Latin legalis. en.wiktionary.org
- Illegal can be analyzed as il- plus legal. en.wiktionary.org
- Immigration senses derive from shortening illegal alien or illegal immigrant. en.wiktionary.org