Merriam-Webster Logo
  • Dictionary
  • Thesaurus
  • Scrabble
  • Spanish Central
  • Learner's Dictionary


adjective il·lic·it \(ˌ)i(l)-ˈli-sət\

Simple Definition of illicit

  • : not allowed by law : unlawful or illegal

  • : involving activities that are not considered morally acceptable

Source: Merriam-Webster's Learner's Dictionary

Full Definition of illicit

  1. :  not permitted :  unlawful

illicitly adverb

Examples of illicit in a sentence

  1. The wedding is mounted in traditional Punjabi style, but underneath the formal fanfare simmer dysfunctional-family tensions, deep dark secrets, … and illicit affairs. —David Ansen, Newsweek, 4 Mar. 2002

  2. “Thank you, Lieutenant,” she said, bowing her head, just as she might in everyday, civilian life, and I felt suddenly illicit in her presence, as though we'd slipped out of sight of our chaperons … —Chang-rae Lee, A Gesture Life, 1999

  3. The companies that carry cellular … have adopted a number of monitoring techniques to detect illicit calls … —Paul Wallich, Scientific American, March 1994

  4. He was arrested for selling illicit copies of the software.

  5. She had an illicit affair with her boss.

Illicit and elicit

Illicit, while not exactly an everyday word, is far more common than its antonym, licit ("not forbidden by law, permissible"). Perhaps this is a function of our oft-noted fascination with bad behavior and boredom with rectitude. In any case, illicit may be used of behavior that is either unlawful or immoral. These categories frequently overlap, but they are not always synonymous, as some unlawful activities (illicit cigarette smoking) may not be considered immoral, while some immoral activities (an illicit affair) are not illegal. Illicit is occasionally confused with elicit because of the similarity in their pronunciations, but the two words have decidedly different meanings and functions: in contemporary English, elicit is a verb meaning "to get (a response, information, etc.) from someone," while illicit appears solely as an adjective.

Origin of illicit

Latin illicitus, from in- + licitus lawful — more at licit

First Known Use: 1506

Rhymes with illicit

ILLICIT Defined for Kids


adjective il·lic·it \i-ˈli-sət\

Definition of illicit for Students

  1. :  not permitted :  unlawful

Law Dictionary


adjective il·lic·it \il-ˈli-sət\

Legal Definition of illicit

  1. :  not permitted :  unlawful <an illicit motive to defeat or evade the taxes — In re Haas, 48 F.3d 1153 (1995)>

Seen and Heard

What made you want to look up illicit? Please tell us where you read or heard it (including the quote, if possible).


to dishevel or rumple

Get Word of the Day daily email!


Take a 3-minute break and test your skills!


Which of these is a synonym of nonplus?

disapprove soothe perplex reduce
Name That Thing

Test your visual vocabulary with our 10-question challenge!


Test Your Knowledge - and learn some interesting things along the way.