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.

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

But when accommodation expands without clear boundaries or meaningful verification, its credibility erodes and skepticism grows about even well-founded uses.

From The Wall Street Journal • Feb. 19, 2026

The big test comes Tuesday, when UnitedHealth reports third-quarter results and investors see whether Warren Buffett’s enthusiasm for the stock was well-founded.

From Barron's • Oct. 27, 2025

And those concerns turned out to be all too well-founded.

From Salon • Aug. 31, 2025

Enquiries based on this premise are bound to conclude that the claims made on behalf of well-founded beliefs are excessive because that conclusion is built into the methodology.

From "The Invention of Science" by David Wootton

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