illicit

adjective

il·​lic·​it (ˌ)i(l)-ˈli-sət 

: not permitted : unlawful

illicit drugs

illicitly adverb

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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.

Synonyms of illicit

• illegal
• unlawful
• criminal

Examples of illicit in a Sentence

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

"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

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

He was arrested for selling illicit copies of the software.

She had an illicit affair with her boss.

Recent Examples on the Web

And while the medical community rejected the compounds, today’s illicit drug manufacturers have revived nitazenes in a far more concentrated and hazardous form. —Josh Meyer, USA Today, 14 May 2026

Reporters crowded around Scott, asking him about Becerra and whether the candidate knew about the illicit arrangement. —Dakota Smith, Los Angeles Times, 14 May 2026

Prosecutors countered by showing police body camera footage from the night of his death in which Kouri Richins tells an officer that her husband had no history of illicit drug use. —Hannah Schoenbaum, Chicago Tribune, 13 May 2026

Some research also suggests the number of people likely to overdose has been shrinking, as fewer teens take up drugs and many illicit drug users have died. —Mike Stobbe, Fortune, 13 May 2026

Word History

Etymology

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

First Known Use

1606, in the meaning defined above

Rhymes for illicit

• complicit
• elicit
• explicit
• implicit
• solicit
• licit

Kids Definition

illicit

adjective

il·​lic·​it (ˈ)il-ˈ(l)is-ət 

: illegal

illicit drug traffic

illicitly adverb

Legal Definition

illicit

adjective

il·​lic·​it il-ˈli-sət 

: not permitted : unlawful

an illicit motive to defeat or evade the taxes

—In re Haas, 48 F.3d 1153 (1995)