Dictionary.com
Thesaurus.com
Synonyms

unfounded

American  
[uhn-faun-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.

See Examples For:

The Civilian Oversight Commission has said that such assertions are unfounded, and that state law and court precedent require its subpoenas to be upheld.

From Los Angeles Times ● Sep. 7, 2026

The recent crescendo of critiques of health messaging is not unfounded.

From Slate ● Aug. 27, 2026

In April, NRL chief executive Andrew Abdo said concerns that a deal between the sport's two leading competitions would lead to a talent drain from Super League were "completely unfounded".

From BBC ● Aug. 13, 2026

Wrries about competition from short-form video have proved to be unfounded, in Pershing Square’s view, and Netflix has deep enough pockets to pay for the higher compute costs that could come from long-form high-quality video.

From MarketWatch ● Aug. 13, 2026

There were still questions about the wheel’s safety, and unfounded stories circulated about suicides and accidents, including one that alleged that a frightened pug had leaped to its death from one of the car’s windows.

From "The Devil in the White City" by Erik Larson

Vocabulary.com logo
by dictionary.com

Look it up. Learn it forever.

Remember new words for good with VocabTrainer. Expand your vocabulary effortlessly with personalized learning tools that adapt to your goals.

Take me to Vocabulary.com