27
prohibited(verb, adjective, adverb, irregular, restricted)
22
verboten(adjective, allow, illegal, allowed, prohibited)
20
banned(verb, adjective, adverb, irregular, restricted)
17
illegal(adjective, adverb, offensive, unreasonable, improper)
16
taboo(adjective, adverb, allow, informal, irregular)
14
proscribed(verb, adjective, irregular, unwarranted, illegitimate)
11
outlawed(verb, adjective, offensive, irregular, unwarranted)
9
illicit(adjective, illegal)
9
unlawful(adjective, illegal)
9
disallowed(verb, adjective, prohibited, excluded)
8
barred(verb, adjective, prohibited, excluded)
8
out of bounds(expression, adjective, idiom, restricted, prohibited)
7
tabu
7
out(adjective, adverb)
6
unauthorized(adjective, illegal)
6
contraband(adjective, unlawful, prohibited, banned, outlawed)
6
interdicted
6
off limits(expression, adjective, idiom, offensive, permitted)
6
unmentionable(adjective, offensive, permitted, prohibited, unspeakable)
5
criminal(adjective, illegal)
<1234510>
11 years ago|11k views|share |citing 
APASmart Define. (2015). forbidden thesaurus. Retrieved September 21, 2026, from https://smartdefine.org/forbidden/thesaurus/synonyms
ChicagoSmart Define. 2015. "forbidden thesaurus" https://smartdefine.org/forbidden/thesaurus/synonyms (accessed September 21, 2026).
HarvardSmart Define 2015, forbidden thesaurus, Smart Define, viewed 21 September, 2026, <https://smartdefine.org/forbidden/thesaurus/synonyms>.
MLASmart Define. "forbidden thesaurus" 10 April 2015. Web. 21 September 2026. <https://smartdefine.org/forbidden/thesaurus/synonyms>