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Synonyms

unfounded

American  
[uhn-foun-did] / ʌnˈfaʊn dɪd /

adjective

  1. without foundation; not based on fact, realistic considerations, or the like.

    unfounded suspicions.

    Synonyms:
    unjustified, false, idle, groundless, unsubstantiated
  2. not established; not founded.

    the prophet of a religion as yet unfounded.


unfounded British  
/ ʌnˈfaʊndɪd /

adjective

  1. (of ideas, allegations, etc) baseless; groundless

  2. not yet founded or established

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Other Word Forms

Etymology

Origin of unfounded

First recorded in 1640–50; un- 1 + found 1 + -ed 2

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.

Keep Reading on Vocabulary.com

Vocabulary lists containing unfounded

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.

The then deputy director, Jonathan Williams, wrote to Gradel five months later to say all the objects were accounted for and his claims were unfounded.

From BBC • Apr. 28, 2026

On the surface, that faith would appear entirely unfounded.

From BBC • Apr. 18, 2026

An organization-wide test in the minors proved those concerns were unfounded.

From The Wall Street Journal • Apr. 15, 2026

The warrants have yet to be released, but they are expected to provide the first glimpse into the contested court documents related to the allegations of fraud — claims that officials say are unfounded.

From Los Angeles Times • Apr. 8, 2026

Now she’d see that her fears were unfounded.

From "In the Time of the Butterflies" by Julia Alvarez