Synonyms of illicit

illicit

adjective

(ˌ)i(l)-ˈli-sət 

as in illegal

contrary to or forbidden by law

had a long history of using illicit drugs

Synonyms & Similar Words

• illegal
• unlawful
• criminal
• felonious
• unauthorized
• wrongful
• forbidden
• illegitimate
• prohibited
• lawless
• immoral
• sinful
• criminalized
• evil
• unethical
• shameful
• wrong
• wicked
• unsanctioned
• bad
• unlicensed
• contraband
• reprehensible
• proscribed
• under-the-table
• outlawed
• unscrupulous
• blameworthy
• corrupt
• discouraged
• barred
• disallowed
• censurable
• interdicted
• banned
• villainous
• unprincipled
• under-the-counter
• bootleg
• blamable
• adulterine

Antonyms & Near Antonyms

• legal
• legitimate
• lawful
• good
• ethical
• right
• permitted
• righteous
• virtuous
• just
• authorized
• principled
• licensed
• approved
• endorsed
• proper
• correct
• allowed
• promoted
• supported
• sanctioned
• decent
• suggested
• encouraged
• abetted
• decorous
• seemly

Example Sentences

Recent Examples of illicit

These digital assets and the underlying technology behind them are forcing investigators and financial institutions to become more sophisticated in tracing this illicit activity. — Mitchell Silber, New York Daily News, 5 Aug. 2026

Environmental crime has become one of the Amazon’s most profitable illicit industries, fueled by global demand for gold, timber and wildlife. — ABC News, 4 Aug. 2026

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