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

Officials with family connections abroad have long been a target of Beijing’s anti-corruption watchdog – oversight designed to eliminate the opportunity to transfer illicit funds abroad. — Sylvie Zhuang, CNN Money, 16 Aug. 2026

Vietnam is a major hub for the illicit trade of wildlife, dead and alive. — Los Angeles Times, 14 Aug. 2026

These included offering greater access to take-home medication and higher doses upon beginning treatment, which can help patients avoid withdrawal and therefore reduce their likelihood of continuing to use illicit substances. — Lev Facher, STAT, 14 Aug. 2026

Vietnam is a major hub for the illicit trade of wildlife, both dead and alive. — ABC News, 13 Aug. 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)