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
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in a thin manner.
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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
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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
-
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
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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:
Instead, it’s a double-decker sandwich with two deli meats, Swiss cheese, coleslaw and Russian dressing, all layered intricately between slices of thin rye bread.
From The Wall Street Journal ● Jul. 28, 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
His head still heavily bandaged, Phineas is roaming about Cavendish in the rain with no coat and thin shoes.
From "Phineas Gage" by John Fleischman
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 Earth's atmospheric pressure is lower, making the air thinner and meaning less oxygen is taken into the bloodstream with each breath.
From BBC ● Jul. 5, 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 crowd is thinner than it will be closer to sunset.
From "The Cruel Prince" by Holly Black
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
“Imperial Valley growers provide the nation with a safe, reliable food supply on the thinnest of margins for many growers,” she said in an email.
From Los Angeles Times ● Dec. 13, 2025
The Air is billed as Apple’s thinnest smartphone yet.
From The Wall Street Journal ● Nov. 8, 2025
I squinted my eyes real, real tight this time, into the thinnest, meanest slits possible, and sent telepathic messages to the workers like, Get away!
From "Ida B" by Katherine Hannigan
The eurozone’s data calendar thins out in the coming week.
From The Wall Street Journal ● Jul. 3, 2026
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
When a tidewater glacier thins enough, it can lift off the seabed and begin floating on the ocean surface.
From Science Daily ● Feb. 26, 2026
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
There were elevated levels of particulate matter recorded in the vicinity of the fire Wednesday afternoon that decreased downwind of the facility as the smoke thinned.
From Los Angeles Times ● Jun. 18, 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
Streaming thinned crowds and big budget films faltered.
From BBC ● Mar. 24, 2026
In the Arctic, however, sea ice has thinned dramatically, with average thickness falling from 3.59 metres in 1975 to 1.25 meters in 2012, according to a 2015 study.
From Barron's ● Mar. 11, 2026
At last the trees thinned, giving way to a sweep of meadow, and they stepped out of the wood into sunlight.
From "Impossible Creatures" by Katherine Rundell
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
Inspired by men’s stories on Bald Café, Christian Makoa, 24, got his head shaved in January because his thinning hair had affected his confidence and he wanted to start dating.
From The Wall Street Journal ● Jun. 24, 2026
Many hair loss treatments are designed mainly to preserve existing hair or slow further thinning.
From Science Daily ● Jun. 7, 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
We’d just rounded the final curve, heading toward the thinning cloud of brand flies near the tram entrance, when a scream split the air.
From "Tristan Strong Punches a Hole in the Sky" by Kwame Mbalia
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.
