16
unfounded(adjective, wrong, fake, false, counterfeit)
14
diseased(adjective, ill, well, unhealthy, unfit)
14
groundless(adjective, foolish, unreasonable, error, reasoning)
14
mad(adjective, wrong, false, silly, foolish)
14
unsafe(adjective, characteristic, quality, finance, dangerous)
14
untenable(adjective, false, reasoning, defended, indefensible)
13
bad(adjective, bad, imperfection)
13
imperfect(adjective, short, imperfection, deficient, broken)
13
incorrect(adjective, bad, correct, wrong, fake)
13
insubstantial(adjective, strong, light, weak, slight)
13
unreasonable(adjective, wrong, false, silly, foolish)
13
unsteady(adjective, weak, uncertain, unstable, ill)
13
unsubstantial(adjective, bad, strong, light, weak)
12
ailing(adjective, weak, delicate, dark, gloomy)
12
damaged(adjective, hurt, deficient, broken, incomplete)
12
delicate(adjective, strong, weak, slight, thin)
12
flimsy(adjective, strong, light, weak, slight)
12
inaccurate(adjective, bad, correct, wrong, fake)
12
sick(adjective, weak, poor, false, inferior)
12
specious(adjective, bad, correct, wrong, fake)
11 years ago|31k views|share |citing 
APASmart Define. (2015). unsound thesaurus. Retrieved September 23, 2026, from https://smartdefine.org/unsound/thesaurus/synonyms
ChicagoSmart Define. 2015. "unsound thesaurus" https://smartdefine.org/unsound/thesaurus/synonyms (accessed September 23, 2026).
HarvardSmart Define 2015, unsound thesaurus, Smart Define, viewed 23 September, 2026, <https://smartdefine.org/unsound/thesaurus/synonyms>.
MLASmart Define. "unsound thesaurus" 14 April 2015. Web. 23 September 2026. <https://smartdefine.org/unsound/thesaurus/synonyms>