illicit

adjective

il·​lic·​it (ˌ)i(l)-ˈli-sət 

1

: not permitted : unlawful, illegal

illicit drugs/substances

illicit profits

2

: involving activities that are not considered morally acceptable

illicit sex

… particularly because she was suspected of having illicit affairs.

—David S. Reynolds

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

Will Hichem stay clean, on the right track when he’s surrounded by people involved in illicit deal-making? — Annika Pham, Variety, 25 Aug. 2026

So, at the very least, any employees motivated by the potential of gaining even higher profits from illicit sales will seemingly be on notice. — Ashley Belanger, ArsTechnica, 24 Aug. 2026

Beijing’s enforcement, although real, is selective and partial because elements of the illicit economy serve the country’s larger strategic goals, such as sustaining trade with Russia while maintaining distance from the war in Ukraine. — Alvin Camba, Foreign Affairs, 21 Aug. 2026

Then again, maybe in Kawhi’s case, even illicit payments are load-managed. — Mike Bianchi, The Orlando Sentinel, 20 Aug. 2026

Word History

Etymology

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

First Known Use

1623, in the meaning defined at sense 1

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)