4
black-market(adjective, illegitimate, pirate, unlawful, prohibited)
4
dirty(adjective, bad, wrong, corrupt, vicious)
4
evil
4
extralegal(adjective, illegitimate, unlawful, prohibited, illicit)
4
false(adjective, wrong, fake, deceitful, worthless)
4
impermissible
4
incorrect(adjective, wrong)
4
unwarrantable(adjective, wrong, unreasonable, improper, excessive)
4
wicked(adjective, wrong, corrupt, unreasonable, dishonest)
3
aberrant(adjective, wrong)
3
abominable
3
against the law(expression, adjective, idiom, wrong, illegitimate)
3
contrary to law(expression, idiom, illicit)
3
corrupt(adjective, bad, wrong, vicious, wicked)
3
flawed(adjective, wrong)
3
forbid
3
misbegotten(adjective, illegitimate, illicit)
3
nonlegal
3
off-limits(adjective, adverb, prohibited, not)
3
off limits(expression, adjective, adverb, offensive, permitted)
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APASmart Define. (2015). illegal thesaurus. Retrieved September 21, 2026, from https://smartdefine.org/illegal/thesaurus/synonyms
ChicagoSmart Define. 2015. "illegal thesaurus" https://smartdefine.org/illegal/thesaurus/synonyms (accessed September 21, 2026).
HarvardSmart Define 2015, illegal thesaurus, Smart Define, viewed 21 September, 2026, <https://smartdefine.org/illegal/thesaurus/synonyms>.
MLASmart Define. "illegal thesaurus" 10 April 2015. Web. 21 September 2026. <https://smartdefine.org/illegal/thesaurus/synonyms>