illegal
Americanadjective
-
forbidden by law or statute.
- Synonyms:
- unlicensed, illicit, illegitimate, unlawful
-
contrary to or forbidden by official rules, regulations, etc..
The referee ruled that it was an illegal forward pass.
noun
adjective
-
forbidden by law; unlawful; illicit
-
unauthorized or prohibited by a code of official or accepted rules
noun
Sensitive Note
See illegal alien.
Related Words
Illegal, unlawful, illegitimate, illicit, criminal can all describe actions not in accord with law. Illegal refers most specifically to violations of statutes or, in organized athletics, codified rules: an illegal seizure of property; an illegal block ( in football ). Unlawful means not sanctioned by or according to law: an unlawful claim to the inheritance; to take unlawful advantage of the trading situation. Illegitimate means lacking legal or traditional right or rights: an illegitimate child; illegitimate use of privileged knowledge. Illicit, which originally meant simply “not permitted,” now most often applies to matters regulated by law with specific emphasis on the way things are carried out: illicit conversion of property; an illicit attempt to control the market. Criminal most often refers to violation of the statutes of penal as opposed to civil law. All felonies are criminal as are all crimes sometimes punishable by death such as murder, arson, and kidnapping: a criminal act.
Other Word Forms
- illegality noun
- illegally adverb
Etymology
Origin of illegal
From the Medieval Latin word illēgālis, dating back to 1620–30. See il- 2, legal
Compare meaning
How does illegal compare to similar and commonly confused words? Explore the most common comparisons:
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.
Oregon’s Worker Fraud Protection Act makes it illegal to “falsely impersonate” a union representative and imposes fines for infractions.
From The Wall Street Journal • Apr. 1, 2026
The Ashley Madison scandal was embarrassing but not illegal.
From Los Angeles Times • Apr. 1, 2026
That’s illegal, and we’re going to get the courts to say so.
From Slate • Mar. 30, 2026
But a northern Greece veterinarian argues that illegal vaccination has helped.
From Barron's • Mar. 30, 2026
Lily said being on the dunes was wrong, even illegal.
From "Caterpillar Summer" by Gillian McDunn
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
