unsound
Americanadjective
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not sound; unhealthy, diseased, or disordered, as the body or mind.
-
decayed or impaired, as timber or foods; defective.
- Synonyms:
- unwholesome, rotten
-
not solid or firm, as foundations.
-
not well-founded or valid; fallacious.
an unsound argument.
-
easily broken; light.
unsound slumber.
-
not financially strong; unreliable.
an unsound corporation.
adjective
-
diseased, weak, or unstable
of unsound mind
-
unreliable or fallacious
unsound advice
-
lacking solidity, strength, or firmness
unsound foundations
-
of doubtful financial or commercial viability
an unsound enterprise
-
(of fruit, timber, etc) not in an edible or usable condition
Other Word Forms
Etymology
Origin of unsound
Middle English word dating back to 1275–1325; see origin at un- 1, sound 2
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.
She’s right about that, but this manual included some unsound science.
From The Wall Street Journal • Feb. 8, 2026
I joke to Shires that, as a man, most often the unsound advice I have received is to simply go look for a rebound.
From Los Angeles Times • Sep. 29, 2025
That assessment was technically accurate but fundamentally unsound.
From Slate • Mar. 28, 2025
It said another team asked to review the recommendations of Amazon's internal safety study had found that the methodology was "unsound".
From BBC • Dec. 16, 2024
The best way to use this information, he thought, was to buy what appeared to be the sounder mortgage bonds and simultaneously sell the unsound ones.
From "The Big Short" by Michael Lewis
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
