thin
Americanadjective
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having relatively little extent from one surface or side to the opposite; not thick.
thin ice.
-
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
-
in a thin manner.
-
sparsely; not densely.
-
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
-
sparsely placed; meagre
thin hair
-
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
-
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
-
is thinningprogressive
-
have been thinningperfect progressive
-
has been thinningperfect progressive
Past
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thinnedsimple
-
had thinnedperfect
-
was thinningprogressive
-
were thinningprogressive
-
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:
"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
Beyond that, Syrian troops are spread thin on their own turf, where power continues to be centralized under the government from various armed factions born out of the civil war.
From The Wall Street Journal ● Jul. 21, 2026
But it is yet another straw in the wind that the stock market is skating on thin ice.
From MarketWatch ● Jul. 21, 2026
The method makes brain tissue transparent, then uses a thin plane of laser light to build a detailed 3D digital image.
From Science Daily ● Jul. 20, 2026
Her sashed suit hung on her thin shoulders as if it were on a hanger.
From "The Red Car to Hollywood" by Jennie Liu
Analysts said generic-drug makers operate on thinner margins and might struggle to move production to the U.S. due to pricing pressures.
From The Wall Street Journal ● Jul. 22, 2026
At that altitude, the Earth's barometric pressure is lower, making the air thinner and meaning less oxygen is taken into the bloodstream with each breath.
From BBC ● Jul. 2, 2026
“This is especially the case given the U.S. holiday on Friday, when liquidity conditions will be a lot thinner, amplifying the impact of any intervention.”
From MarketWatch ● Jul. 2, 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
He had a wide smile and was taller and thinner than I’d imagined he’d be—a man who was clearly not much of an eater, who also looked fully unaccustomed to wearing business clothes.
From "Becoming" by Michelle Obama
And the U.S. is meeting this challenge with the thinnest oil-reserve cushion in a generation.
From MarketWatch ● Jul. 21, 2026
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
The Angels’ minor league system is widely regarded as one of baseball’s thinnest.
From Los Angeles Times ● Nov. 11, 2025
The Air is billed as Apple’s thinnest smartphone yet.
From The Wall Street Journal ● Nov. 8, 2025
Even Bowdy was too scared to step on the thinnest branches.
From "The Absolutely True Diary of a Part-Time Indian" by Sherman Alexie
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 eurozone data calendar thins out after the usual end-of-month avalanche.
From The Wall Street Journal ● Feb. 27, 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
She has keratoconus - a condition where the cornea thins and bulges, causing distorted and blurred vision.
From BBC ● Oct. 18, 2024
At thirty weeks her skin thins, and her hair gets thicker.
From "Middlesex: A Novel" by Jeffrey Eugenides
The "first rung of the career ladder has thinned" and that for "too many young people it is now simply out of reach", Milburn is set to say in a speech later.
From BBC ● May 27, 2026
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
Some glaciers have thinned so much that they may no longer be able to build up enough ice to surge again.
From Science Daily ● Apr. 17, 2026
The wool thinned and tightened and transformed into yarn, as if by magic.
From "Rump: The (Fairly) True Story of Rumpelstilskin" by Liesl Shurtliff
They said that issues such as "chronic under-investment in forest thinning, fuel reduction, and prescribed burns, along with inadequate enforcement against arson", had not been addressed "adequately enough".
From BBC ● Jul. 17, 2026
Many hair loss treatments are designed mainly to preserve existing hair or slow further thinning.
From Science Daily ● Jun. 7, 2026
Many of the same tech companies had powered the indexes to records this year, a grim reminder of the market’s dependence on a thinning group of top performers.
From The Wall Street Journal ● Jun. 5, 2026
These includes fortifying homes against wildfires, replanting fire-ravaged forests and thinning out vegetation with prescribed burns, goat grazing and manual thinning with heavy machinery to reduce the intensity of potential fires.
From Los Angeles Times ● May 30, 2026
She says, “Now, I’m also going to get permission from Drum and order you some new pants. You’re thinning out and shooting up. And you’re going to need a razor because your chin is fuzzy.”
From "The Truth as Told by Mason Buttle" by Leslie Connor
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.
