unfounded
Americanadjective
-
without foundation; not based on fact, realistic considerations, or the like.
unfounded suspicions.
- Synonyms:
- unjustified, false, idle, groundless, unsubstantiated
-
not established; not founded.
the prophet of a religion as yet unfounded.
adjective
-
(of ideas, allegations, etc) baseless; groundless
-
not yet founded or established
Other Word Forms
- unfoundedly adverb
- unfoundedness noun
Etymology
Origin of unfounded
Explanation
Has someone ever told a complete lie about you? Then what they said was unfounded. There is nothing behind an unfounded statement. Things that are unfounded include lies, myths, and sometimes rumors. If something is unfounded, then there is no truth to it: the facts won't back it up. People often use this word when denying something: they'll say "Your words are unfounded!" Made-up creatures like unicorns and werewolves are unfounded. If you're writing a paper for school, you've better make sure nothing in your paper is unfounded — research the facts instead.
Vocabulary lists containing unfounded
Fake It 'Til You Make It: Synonyms for "False"
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100 SAT Words Beginning with "U"
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"Laws are not the only way to boost immunization”: an editorial from Nature
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Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
On the surface, that faith would appear entirely unfounded.
From BBC • Apr. 18, 2026
Reading an extraordinary statement at the White House, she denied any association with Epstein and said, “My attorneys and I have fought these unfounded and baseless lies with success.”
From Los Angeles Times • Apr. 9, 2026
To support the unfounded allegation, they circulated screenshots on social media showing results from JustDone.
From Barron's • Mar. 30, 2026
"By shedding light on the biology and ecology of the great white shark, research can help replace unfounded myths with genuine understanding."
From Science Daily • Mar. 11, 2026
Among the most progressive alienists, this kind of unfounded belief was known as a delusion, associated with a newly identified disorder called paranoia.
From "The Devil in the White City" by Erik Larson
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
