Synonyms

well-founded

American

[wel-foun-did] / ˈwɛlˈfaʊn dɪd /

adjective

having a foundation in fact; based on good reasons, information, etc..

well-founded suspicions.

well-founded British

adjective

having good grounds

well-founded rumours

"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

Etymology

Origin of well-founded

Middle English word dating back to 1325–75

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 employment tribunal found his claims were "not well-founded".

From BBC • Jun. 2, 2026

But most current estimates of future inflation fall within a narrow range, giving us at least some confidence that the real yields based on those estimates are well-founded.

From MarketWatch • Apr. 8, 2026

It encapsulates the well-founded belief that starting a war is likely to create unforeseen evils greater than the evil of the status quo.

From Salon • Mar. 14, 2026

My working theory is that they tap into audiences with a preexisting suspicion that the world is wicked — they prove paranoia to be well-founded.

From Los Angeles Times • Mar. 11, 2026

SNAPE: I’d say that the rumors of Hogwarts’s beloved Scorpion King losing his mind are well-founded.

From "Harry Potter and the Cursed Child" by J.K. Rowling

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023