7
baseless(adjective, poor, negative, untrue, vacant)
7
groundless(adjective, poor, negative, error, unwarranted)
5
unwarranted(adjective, right, reasonable)
4
unfounded
3
erroneous(adjective, bad, false, mad, unreasonable)
3
fallacious(adjective, bad, wrong, poor, false)
3
false(adjective, bad, poor, error, incorrect)
3
flimsy(adjective, poor, negative, unwarranted, untrue)
3
gratuitous
3
ill-founded
2
apocryphal(adjective, error)
2
idle
2
illogical(poor, mad, unreasonable, error, irrational)
2
uncalled-for
2
unreal(adjective, negative, mad, unreasonable, error)
2
unsustainable
1
beguiling(mad, unreasonable, irrational)
1
bottomless
1
built on sand(expression, idiom)
1
causeless
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APASmart Define. (2015). ungrounded thesaurus. Retrieved September 20, 2026, from https://smartdefine.org/ungrounded/thesaurus/synonyms
ChicagoSmart Define. 2015. "ungrounded thesaurus" https://smartdefine.org/ungrounded/thesaurus/synonyms (accessed September 20, 2026).
HarvardSmart Define 2015, ungrounded thesaurus, Smart Define, viewed 20 September, 2026, <https://smartdefine.org/ungrounded/thesaurus/synonyms>.
MLASmart Define. "ungrounded thesaurus" 14 April 2015. Web. 20 September 2026. <https://smartdefine.org/ungrounded/thesaurus/synonyms>