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Definitions

unfounded

[uhn-foun-did] / ʌnˈfaʊn dɪd /
ADJECTIVE
not based on fact
Synonyms
STRONGEST
baseless deceptive fabricated false gratuitous groundless illogical misleading spurious unjustified unproven unsubstantiated untrue untruthful unwarranted
WEAK
fallacious foundationless idle mendacious off-base trumped-up uncalled-for unreal vain without basis without foundation
Antonyms
STRONGEST
called-for correct genuine honest justified real reasonable right true truthful warranted
WEAK
founded proven substantiated supported

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.

Levy: I have a completely unfounded fear of being trapped in an organized criminal situation.

From Los Angeles Times • Apr. 1, 2026

To support the unfounded allegation, they circulated screenshots on social media showing results from JustDone.

From Barron's • Mar. 30, 2026

Some criticisms of the accelerated approval pathway aren’t unfounded.

From The Wall Street Journal • Mar. 3, 2026

In a letter to the police, seen by the BBC, their lawyers say the family are co-operating with "criminal proceedings", but maintain the allegations are "unfounded and unsupported by credible evidence".

From BBC • Feb. 17, 2026

As it turns out, her fears were unfounded.

From "The New Jim Crow" by Michelle Alexander

From Roget's 21st Century Thesaurus, Third Edition Copyright © 2013 by the Philip Lief Group.