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
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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
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diseased, weak, or unstable
of unsound mind
-
unreliable or fallacious
unsound advice
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lacking solidity, strength, or firmness
unsound foundations
-
of doubtful financial or commercial viability
an unsound enterprise
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(of fruit, timber, etc) not in an edible or usable condition
Other Word Forms
- unsoundly adverb
- unsoundness noun
Etymology
Origin of unsound
Middle English word dating back to 1275–1325; 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
That assessment was technically accurate but fundamentally unsound.
From Slate • Mar. 28, 2025
In a brief filed to the court, he called the firm's arguments "meritless and unsound."
From BBC • Dec. 18, 2024
The surface pleasures of “Y2K” are outlandishly fun, but plot-wise, the film is structurally unsound.
From Los Angeles Times • Dec. 6, 2024
Bishop Colenso, whose views on everything were considered unsound that day and are archaic in this, was the little dean’s particular pet.
From "Go Set a Watchman: A Novel" by Harper Lee
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.
