38
unlawful(adjective, adverb, law, wrong, corrupt)
30
criminal(adjective, wrong, evil, dishonest, illegitimate)
28
illicit(adjective, adverb, law, criminal, legal)
25
illegitimate(adjective, law, wrong, corrupt, vicious)
24
unauthorized(adjective, permitted, illegitimate, prohibition, sanctioned)
22
prohibited(adjective, adverb, offensive, permitted, illegitimate)
18
wrongful(adjective, law, corrupt, dishonest, unwarranted)
16
felonious(adjective, wrong, wicked, senseless, criminal)
16
wrong(adjective, wrong, dishonest, immoral, worthless)
13
forbidden(verb, adjective, adverb, offensive, unreasonable)
11
lawless(adjective, law, wrong, wicked, senseless)
11
crooked(adjective, bad, wrong, fake, corrupt)
10
unlicensed(adjective, illegitimate, prohibition, pirate, unlawful)
10
outlawed(adjective, law, offensive, permitted, illegitimate)
10
verboten
9
taboo(adjective, permitted, allowed)
9
irregular
8
actionable(adjective, illegality)
8
unjust(adjective, wicked, unreasonable, dishonest, immoral)
7
banned(adjective, adverb, offensive, permitted, illegitimate)
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APASmart Define. (2015). illegal thesaurus. Retrieved September 20, 2026, from https://smartdefine.org/illegal/thesaurus/synonyms
ChicagoSmart Define. 2015. "illegal thesaurus" https://smartdefine.org/illegal/thesaurus/synonyms (accessed September 20, 2026).
HarvardSmart Define 2015, illegal thesaurus, Smart Define, viewed 20 September, 2026, <https://smartdefine.org/illegal/thesaurus/synonyms>.
MLASmart Define. "illegal thesaurus" 10 April 2015. Web. 20 September 2026. <https://smartdefine.org/illegal/thesaurus/synonyms>