unfounded

adjective

ˌən-ˈfau̇n-dəd How to pronounce unfounded (audio)
Definition of unfoundednext
as in unreasonable
having no basis in reason or fact the accusation proved to be unfounded

Synonyms & Similar Words

Relevance

Antonyms & Near Antonyms

Example Sentences

Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Recent Examples of unfounded Supporters of the rule change also spoke against the COVID vaccine and the measles, mumps and rubella vaccine (MMR), repeating unfounded claims, such as that doctors make money from vaccines and that vaccines cause autism. — Ana Goñi-Lessan, Sun Sentinel, 8 Oct. 2026 In the lead-up to the 2022 vote, Jair Bolsonaro repeatedly cast unfounded doubts on Brazil's electronic voting system. — Arkansas Online, 4 Oct. 2026 Alito’s concerns are not unfounded, as threats to members in recent history have raised alarm about justices’ safety. — Claire Carter, The Washington Examiner, 4 Oct. 2026 In the lead-up to the 2022 vote, Jair Bolsonaro repeatedly cast unfounded doubts on Brazil’s electronic voting system. — Eléonore Hughes, Los Angeles Times, 3 Oct. 2026 See All Example Sentences for unfounded
Recent Examples of Synonyms for unfounded
  1. unreasonable
  2. baseless
  3. groundless
  4. unsubstantiated
  5. unwarranted
Adjective
  • On the surface, paying as low as 24 cents for an hour of streaming game time doesn’t sound completely unreasonable.
    — Kyle Orland, ArsTechnica, 21 Oct. 2026
  • If Putin rejects the framework — or, more likely, demands unreasonable changes — then the world will at least know who blocked the fledgling peace effort.
    — David Ignatius, Washington Post, 21 Oct. 2026
Definition of unreasonable
Adjective
  • Trump unleashed a series of personal and baseless attacks against Hamilton at the rally in Park City, Kansas -- about 10 miles north of Wichita -- with just two weeks out from election day as the balance of power in the Senate hangs in the balance.
    — ABC News, ABC News, 20 Oct. 2026
  • The White House has consistently derided Bonta’s litigation against the administration as baseless and misguided.
    — Kevin Rector, Los Angeles Times, 15 Oct. 2026
Definition of baseless
Adjective
  • Ye Khaung Kyaw and the two other men charged in connection with the case have said the accusations against them are groundless.
    — Arkansas Online, Arkansas Online, 24 Sep. 2026
  • Social media in South Korea have been filled with messages stoking fears about safety on Jeju, with some spreading groundless rumors and deriding the island.
    — Hyung-Jin Kim, Los Angeles Times, 27 Aug. 2026
Definition of groundless
Adjective
  • Internal affairs complaints The lawsuit identifies five internal complaints filed against Sumstad between December 2022 and October 2025 and alleges each was dismissed, deemed unsubstantiated or ended in her exoneration.
    — Ben Wheeler, Kansas City Star, 24 Sep. 2026
  • Somehow this unsubstantiated story became internationally known with almost no major media explicitly reporting it, and before the modern version of the internet.
    — Allen Salkin, HollywoodReporter, 14 Sep. 2026
Definition of unsubstantiated
Adjective
  • While we are relieved that Heidi has received medical care and is safe, we are outraged by this unwarranted attack on a journalist doing her job and urge a thorough investigation and follow-through from authorities.
    — Arkansas Online, Arkansas Online, 17 Oct. 2026
  • Critics have argued that much of the data collected is from people who are not suspected of any wrongdoing, amounting to unwarranted surveillance of lawful activities.
    — Carlos E. Castañeda, CBS News, 29 Sep. 2026
Definition of unwarranted

Browse Nearby Words

unfortunately
unfounded
unfree
See all Nearby Words

Cite this Entry

“Unfounded.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/unfounded. Accessed 27 Oct. 2026.

Copy Citation
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

Last Updated: - Updated example sentences

More from Merriam-Webster

Word of the Day

Listen to the pronunciation of milieu

See Definitions and Examples »

Popular in Grammar & Usage

See More

How to Use 'Who' vs. 'Whom'

Merriam-Webster’s Great Big List of Words You Love to Hate

'Affect' vs. 'Effect'

'A' or 'an'? What about before 'h'? An Indefinite Article Guide

Why is '-ed' sometimes pronounced at the end of a word?
See More

Popular in Wordplay

See More

The Longest Long Words List

9 Words That Sound Like Insults But Aren't

12 Lovely and Unusual Words for the Natural World

Why do we 'bury the lede?'

'Za' and 9 Other Words to Help You Win at SCRABBLE
See More

Popular

See More

How to Use 'Who' vs. 'Whom'

The Longest Long Words List

9 Words That Sound Like Insults But Aren't
See More

Games & Quizzes

See All
Play Quordle: Guess all four words in a limited number of tries. Each of your guesses must be a real 5-letter word.
Quordle Can you solve 4 words at once?
Play Blossom: Solve today's spelling word game by finding as many words as you can using just 7 letters. Longer words score more points.
Blossom Pick the best words!
Play Missing Letter: a crossword with a twist. Each of the 25 puzzle words start with a different letter of the alphabet. Which letter is missing?
The Missing Letter A daily crossword with a twist
different halloween monsters in silhouette
A Monstrous Vocab Quiz Words That Go Bump in the Night
See All