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

An astounding one-third to one-quarter of all fuel sold in Mexico may be illicit. — Shi Bradley, Los Angeles Times, 3 Aug. 2026

Among 12-to-17-year-olds, the survey showed a drop in those who reported tobacco, alcohol and binge drinking in the past month and the use of illicit drugs in the past year. — Mary Kekatos, ABC News, 1 Aug. 2026

The illicit activity has caused utilities to issue boil-water notices and switch water systems from automatic to manual modes. — Joey Garrison, USA Today, 31 July 2026

Concurrently, the Revolutionary Guard Corps (IRGC) built a multi-billion-dollar business empire spanning oil, banking, and real estate, engaging in illicit smuggling and sanction-bypassing oil sales, generating billions annually. — Natasha Lindstaedt, Forbes.com, 29 July 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)