| sneaky(adjective, sly, fraudulent) | |
| unjust(adjective, illegal) | |
| unofficial | |
| back-door | |
| foul | |
| guilty(adjective, legal, forbidden) | |
| heavy(adjective, wrong, informal, irregular, senseless) | |
| interdicted | |
| off-limits(adjective, adverb, prohibited, not) | |
| off limits | |
| out of bounds(expression, adjective, idiom) | |
| pirate | |
| proscribed | |
| tabu | |
| unallowed | |
| under-the-counter(hidden, sly, illegal, fraudulent, illegitimate) | |
| unwarrantable(irregular, unwarranted, criminal, illegal, illegitimate) | |
| unwarranted | |
| villainous(adjective, wrong, wicked, criminal, illegal) | |
| wicked(adjective, wrong, criminal, illegal, unlawful) |
For more, visit
Illicit on
Power Thesaurus
| APA | Smart Define. (2015). illicit thesaurus. Retrieved September 22, 2026, from https://smartdefine.org/illicit/thesaurus/synonyms |
| Chicago | Smart Define. 2015. "illicit thesaurus" https://smartdefine.org/illicit/thesaurus/synonyms (accessed September 22, 2026). |
| Harvard | Smart Define 2015, illicit thesaurus, Smart Define, viewed 22 September, 2026, <https://smartdefine.org/illicit/thesaurus/synonyms>. |
| MLA | Smart Define. "illicit thesaurus" 13 April 2015. Web. 22 September 2026. <https://smartdefine.org/illicit/thesaurus/synonyms> |