illicit
Americanadjective
-
not legally permitted or authorized; unlicensed; unlawful.
- Synonyms:
- prohibited, illegitimate
-
disapproved of or not permitted for moral or ethical reasons.
adjective
-
another word for illegal
-
not allowed or approved by common custom, rule, or standard
illicit sexual relations
Synonym Usage
See illegal.
Other Word Forms
Etymology
Origin of illicit
First recorded in 1645–55; from Latin illicitus, equivalent to il- 2 + licit ( def. )
Compare meaning
How does illicit compare to similar and commonly confused words? Explore the most common comparisons:
Explanation
Illicit means not allowed by law or custom. It's illegal to kill endangered elephants, but many poachers still engage in the Illicit ivory trade. Illicit usually refers to something that is not morally proper or acceptable. Illicit activities — like smuggling or counterfeiting — happen under the radar of the law. Illicit is from Latin illicitus, from the prefix in-, "not," plus licitus, "lawful."
Vocabulary lists containing illicit
Some Tricky Homonyms
Looking to grow your vocabulary? Check out this interactive, curated word list from our team of English language specialists at Vocabulary.com – one of over 17,000 lists we've built to help learners worldwide!
This Week in Words: September 1 - 7, 2018
Interested in learning more words like this one? Our team at Vocabulary.com has got you covered! You can review flashcards, quiz yourself, practice spelling, and more – and it's all completely free to use!
Brave New World
Want to remember this word for good? Start your learning journey today with our library of interactive, themed word lists built by the experts at Vocabulary.com – we'll help you make the most of your study time!
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.
Sun says Tron has innovated new collaborations with law enforcement to tackle illegal transactions on the blockchain, leading to huge declines in illicit volume on the platform.
From BBC ● Jul. 10, 2026
Interpol Secretary Valdecy Urquiza said human trafficking remained "one of the most profitable and pervasive forms" of organised crimes, generating billions in illicit revenue each year.
From BBC ● Jul. 6, 2026
L.A.’s love of fireworks makes for a colorful Fourth of July, with dozens of official celebrations and countless illicit explosions expected for the holiday.
From Los Angeles Times ● Jul. 4, 2026
Obrokta denied making the comment and said he never gave any illicit benefits to any player.
From The Wall Street Journal ● Jun. 28, 2026
As it is, this illicit reading of mine seems a kind of performance.
From "The Handmaid's Tale" by Margaret Atwood
![]()
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.