thin
Americanadjective
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having relatively little extent from one surface or side to the opposite; not thick.
thin ice.
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of small cross section in comparison with the length; slender.
a thin wire.
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having little flesh; spare; lean.
a thin man.
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composed of or containing objects, particles, etc., widely separated; sparse.
thin vegetation.
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scant; not abundant or plentiful.
- Synonyms:
- meager
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of relatively slight consistency or viscosity.
thin soup.
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rarefied, as air.
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without solidity or substance; flimsy.
a very thin plot for such a long book.
- Synonyms:
- weak
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lacking fullness or volume; weak and shrill.
a thin voice.
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without force or a sincere effort.
a thin smile.
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lacking body, richness, or strength.
a thin wine.
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lacking in chroma; of light tint.
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Photography. (of a developed negative) lacking in density or contrast through underdevelopment or underexposure.
adverb
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in a thin manner.
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sparsely; not densely.
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so as to produce something thin.
Slice the ham thin.
verb (used with object)
verb (used without object)
adjective
-
of relatively small extent from one side or surface to the other; fine or narrow
-
slim or lean
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sparsely placed; meagre
thin hair
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of relatively low density or viscosity
a thin liquid
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weak; poor; insufficient
a thin disguise
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(of a photographic negative) having low density, usually insufficient to produce a satisfactory positive
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mountaineering a climb or pitch on which the holds are few and small
-
few in number; scarce
adverb
verb
Synonym Usage
Thin, gaunt, lean, spare agree in referring to one having little flesh. Thin applies often to one in an unnaturally reduced state, as from sickness, overwork, lack of food, or the like: a thin, dirty little waif. Gaunt suggests the angularity of bones prominently displayed in a thin face and body: to look ill and gaunt. Lean usually applies to a person or animal that is naturally thin: looking lean but healthy after an outdoor vacation. Spare implies a muscular leanness with no diminution of vitality: Lincoln was spare in body.
Other Word Forms
Derived Forms
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overthinnessnoun
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thinnessnoun
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overthinadjective
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self-thinningadjective
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superthinadjective
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unthinnedadjective
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unthinningadjective
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overthinlyadverb
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thinlyadverb
Inflected Forms
Adjectives
Participles
Conjugated Forms
Present
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thinsimple
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thinssimple
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have thinnedperfect
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has thinnedperfect
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am thinningprogressive
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are thinningprogressive
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is thinningprogressive
-
have been thinningperfect progressive
-
has been thinningperfect progressive
Past
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thinnedsimple
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had thinnedperfect
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was thinningprogressive
-
were thinningprogressive
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had been thinningperfect progressive
Future
Etymology
Origin of thin
First recorded before 900; (adjective and adverb) Middle English thyn(ne), Old English thynne; cognate with Dutch dun, German dünn, Old Norse thunnr; (verb) Middle English thynnen, Old English thynnian, derivative of the adjective; compare Middle Dutch dunnen, Old Norse thynna; akin to Old Irish tana, Latin tenuis thin, Greek tany- long
Explanation
Something thin is narrow or not very thick. If you wear thin socks on a cold winter day, your toes might start to feel numb. Thin can describe something that is narrow and slender, like a hair or a thread. It can also describe a layer of something that is not very thick, such as paper. To thin something out is to make it lesser or weaker, like thinning out a sauce by adding water. You can also use this word figuratively. An argument that is not very convincing is thin.
Vocabulary lists containing thin
The SAT: Multiple-Meaning Words, List 4
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The New SAT: Multiple-Meaning Words
Interested in learning more words like this one? Our team at Vocabulary.com has got you covered! You can review flashcards, quiz yourself, practice spelling, and more – and it's all completely free to use!
The ACT Reading Test: Multiple-Meaning Words, List 4
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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.
See Examples For:
By comparison, “Sheep in the Box” feels thin and strangely scattershot in its approach to a drama that ought to have profound implications.
From The Wall Street Journal ● Jul. 23, 2026
But for Lurie, the argument that demand should inevitably lead to a stamp of approval falls short given the "extremely thin science."
From Barron's ● Jul. 23, 2026
"An important link in the chain has just vanished into thin air, without there even having been a chance to recover the information Daniel Siad might have possessed—given that he was never questioned," she said.
From BBC ● Jul. 22, 2026
But it is yet another straw in the wind that the stock market is skating on thin ice.
From MarketWatch ● Jul. 21, 2026
At once I realized that we were on ice, thin ice, no more than a couple of inches thick.
From "Black Star, Bright Dawn" by Scott O'Dell
By pairing these therapies with weight-loss medications, Yancopoulos hopes to focus on the quality of weight reduction so patients get stronger rather than just thinner.
From The Wall Street Journal ● Jul. 24, 2026
The findings, published in ACS Nano on July 16, 2026, suggest that collagen begins losing its precise molecular organization before its fibers become thinner, fragmented, or disconnected.
From Science Daily ● Jul. 20, 2026
Turbines need oxygen to burn gas, but hot air tends to be thinner, reducing the efficiency of the turbines.
From Barron's ● Jun. 30, 2026
Retailers are likely slower to pass along savings to make up for thinner margins when gas prices spiked in March and April, he noted.
From MarketWatch ● Jun. 24, 2026
The coastal city was shaped like an arc that grew thinner on both ends until the tips stabbed into the sea.
From "Tristan Strong Punches a Hole in the Sky" by Kwame Mbalia
But I also looked in at myself as a mother through the leaded-glass pane of our very lovely living-room windows, and I saw a washed-out woman worn down to the thinnest thread.
From Slate ● Jul. 6, 2026
Value is concentrated exactly where capacity is thinnest.
From MarketWatch ● Jul. 1, 2026
Powell has sided with the doves since the jobs picture darkened in August, but the dissents and hawkish guidance underscored how he is navigating with the thinnest internal support of his tenure.
From The Wall Street Journal ● Dec. 10, 2025
It was believed to be the time when the veil between the living and the dead was at its thinnest and spirits roamed the earth.
From BBC ● Oct. 31, 2025
She and Uncle Vernon went off to the lumpy bed next door, and Harry was left to find the softest bit of floor he could and to cud up under the thinnest, most ragged blanket.
From "Harry Potter and the Sorcerer's Stone" by J.K. Rowling
Buying equity stakes rather than owning depreciating fleets softens that, but the line between “demand layer” and “co-investor in hardware” thins with each deal.
From MarketWatch ● Jun. 24, 2026
The term describes how the crust stretches and thins in the middle, similar to the narrowed "neck" that forms when a piece of saltwater taffy is pulled apart.
From Science Daily ● Apr. 25, 2026
On the other hand, “too many to keep track of and care for thins out your time for everyone,” he says.
From The Wall Street Journal ● Mar. 23, 2026
As a devastating outbreak of bird flu thins chicken populations and market forces drive grocery prices up, the breakfast and baking staple has become pricier and harder to find.
From Los Angeles Times ● Feb. 13, 2025
At last the wind blows, the whiteness thins, and the blue jay catches sight of me.
From "On the Far Side of the Mountain" by Jean Craighead George
One franchisee operating several beverage stores in Henan province said sales volumes remained high but profits had thinned sharply over the past two years because “everyone nearby is running promotions all the time.”
From Barron's ● May 26, 2026
More recently, he made his entire corporate staff reapply for their jobs, then thinned out the ranks by letting a few dozen employees go.
From The Wall Street Journal ● May 10, 2026
The monoculture that once lifted “Euphoria” has thinned, if it even exists at all.
From Los Angeles Times ● Apr. 9, 2026
Streaming thinned crowds and big budget films faltered.
From BBC ● Mar. 24, 2026
And, as Will watched, the ice cube that had appeared from nothing only moments before evaporated to mist inside the jar, and then thinned into a haze, and then disappeared completely.
From "A Tangle of Knots" by Lisa Graff
Last month, when pressed on the subject, Hegseth denied that supplies were thinning out.
From BBC ● Jul. 27, 2026
"Unlike Californian forests, where preventative measures can be taken through thinning, boreal forests, which are very dense, cannot be controlled," Bergeron said.
From Barron's ● Jul. 20, 2026
Earlier research has raised concerns that rapid weight loss associated with GLP-1 medications may contribute to bone thinning and increase fracture risk.
From Science Daily ● Jun. 16, 2026
Yet, as Robert Macfarlane and Jackie Morris tell us in “The Book of Birds: A Field Guide to Wonder and Loss,” “a great thinning of the skies is under way.”
From The Wall Street Journal ● Jun. 12, 2026
I fell a couple of times, tripping over roots sticking out from ground that was ashy and loose in the thinning earth, washed out from the endless rain.
From "The Marrow Thieves" by Cherie Dimaline
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.
