thin

American  

[thin] / θɪn /

adjective

• thinner,
  comparative
• thinnest
  superlative

1. having relatively little extent from one surface or side to the opposite; not thick.

   thin ice.

2. of small cross section in comparison with the length; slender.

   a thin wire.

3. having little flesh; spare; lean.

   a thin man.

   Synonyms:

   scrawny, lank, skinny, slender, slim

4. composed of or containing objects, particles, etc., widely separated; sparse.

   thin vegetation.

5. scant; not abundant or plentiful.

   Synonyms:

   meager

6. of relatively slight consistency or viscosity.

   thin soup.

7. rarefied, as air.

8. without solidity or substance; flimsy.

   a very thin plot for such a long book.

   Synonyms:

   weak

9. lacking fullness or volume; weak and shrill.

   a thin voice.

10. without force or a sincere effort.

    a thin smile.

11. lacking body, richness, or strength.

    a thin wine.

12. lacking in chroma; of light tint.

13. Photography. (of a developed negative) lacking in density or contrast through underdevelopment or underexposure.

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adverb

1. in a thin manner.

2. sparsely; not densely.

3. so as to produce something thin.

   Slice the ham thin.

verb (used with object)

• thins,
  present (3rd person singular)
• thinned,
  past participle,  past
• thinning
  present participle

1. to make thin or thinner (often followed by down, out, etc.).

verb (used without object)

• thins,
  present (3rd person singular)
• thinned,
  past participle,  past
• thinning
  present participle

1. to become thin or thinner; become reduced or diminished (often followed by down, out, off, etc.).

   The crowd is thinning out.

thin British  

/ θɪn /

adjective

1. of relatively small extent from one side or surface to the other; fine or narrow

2. slim or lean

3. sparsely placed; meagre

   thin hair

4. of relatively low density or viscosity

   a thin liquid

5. weak; poor; insufficient

   a thin disguise

6. (of a photographic negative) having low density, usually insufficient to produce a satisfactory positive

7. mountaineering a climb or pitch on which the holds are few and small

8. few in number; scarce

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adverb

1. in order to produce something thin

   to cut bread thin

verb

1. to make or become thin or sparse

thin Idioms  

More idioms and phrases containing thin

• into thin air
• on thin ice
• spread oneself too thin
• through thick and thin
• wear thin

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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

• overthinness
  noun
• thinness
  noun
• overthin
  adjective
• self-thinning
  adjective
• superthin
  adjective
• unthinned
  adjective
• unthinning
  adjective
• overthinly
  adverb
• thinly
  adverb

Inflected Forms

Adjectives

• thinner
  comparative
• thinnest
  superlative

Participles

• thinning
  present
• thinned
  past

Conjugated Forms

Present

• thin
  simple
• thins
  simple
• have thinned
  perfect
• has thinned
  perfect
• am thinning
  progressive
• are thinning
  progressive
• is thinning
  progressive
• have been thinning
  perfect progressive
• has been thinning
  perfect progressive

Past

• thinned
  simple
• had thinned
  perfect
• was thinning
  progressive
• were thinning
  progressive
• had been thinning
  perfect progressive

Future

• will thin
  simple
• will have thinned
  perfect
• will be thinning
  progressive
• will have been thinning
  perfect progressive

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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

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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.

Example Sentences

See Examples For:

thin thinner thinnest thins thinned thinning

Close to 1 in 4 homeowners is “house rich” and stretched thin everywhere else, and that usually includes retirement accounts.

From MarketWatch ● Oct. 26, 2026

"The margins are so thin that you can't make a lot of mistakes," a logging manager said.

From Barron's ● Oct. 26, 2026

This millennial was also a fan: I personally fell for the zesty Linguica sausages and the Picanha steak, which is sliced thin and seasoned with rock salt.

From The Wall Street Journal ● Oct. 25, 2026

Cell membranes are thin, flexible barriers made largely from fatty molecules called lipids.

From Science Daily ● Oct. 24, 2026

She was tall and thin and not too old.

From "Firegirl" by Tony Abbott

As a result, the Arctic is increasingly covered by thinner first-year ice, which forms during the cold months but is more susceptible to melting when summer returns.

From Science Daily ● Oct. 15, 2026

But he became increasingly conscious of his condition as he grew older, particularly as hairstyles changed and his hair became thinner.

From BBC ● Oct. 13, 2026

Cartilage in the knees of older animals had been noticeably thinner and less functional than cartilage in young mice.

From Science Daily ● Oct. 6, 2026

Newspapers can become thinner and health care more Byzantine in ways that are difficult to trace back to an investment firm.

From Salon ● Oct. 3, 2026

It had been the hardest winter since records began; the Red Army was stretched even thinner than it had been at the beginning of the war.

From "A Thousand Sisters" by Elizabeth Wein

“I couldn’t eat. I was the thinnest I’d ever been. I was just so anxious every day, not having answers to these questions,” Bayouth said.

From Los Angeles Times ● Jul. 29, 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

Value is concentrated exactly where capacity is thinnest.

From MarketWatch ● Jul. 1, 2026

A 120,000-year-old deer skeleton, also discovered in Germany, shows a spear wound where the pelvic bone was thinnest, suggesting that the hunter knew exactly where to aim.

From The Wall Street Journal ● Apr. 30, 2026

She swallowed her nervousness and tied an end of the thinnest, lightest line to one of her arrows, and sent it flying upward from the bow.

From "The Amber Spyglass" by Philip Pullman

In this cosmic battle, dark energy appears to be winning — expanding our universe over trillions of years until everything thins and smooths out into almost nothingness.

From Los Angeles Times ● Aug. 28, 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

Along the outer edges, red hues trace the coldest material, where gas thins and dust begins to take shape.

From Science Daily ● Jan. 26, 2026

The challenge of social isolation intensifies with age as children move out and retirement thins daily contact.

From The Wall Street Journal ● Oct. 13, 2025

Sirens echo through the neighborhood, and the crowd instantly thins out, with people scattering everywhere.

From "Like Vanessa" by Tami Charles

The largest trees in the thinned stands were 20% bigger in diameter than those in the unharvested control areas.

From Science Daily ● Oct. 4, 2026

But it’s especially bad for big agricultural states, where margins were already thinned due to tariffs and fertilizer prices.

From Slate ● Sep. 26, 2026

The yen’s moves on Monday may rekindle market chatter about potential intervention, particularly as authorities have in the past taken advantage of thinned liquidity during public holidays to step in.

From The Wall Street Journal ● Sep. 7, 2026

To avert future calamities, the forest outside Bordeaux must be thinned and its fire breaks widened, said Arthur Guérin-Turcq, a Sorbonne University geographer whose family cultivates pines near Le Porge.

From Los Angeles Times ● Aug. 30, 2026

“This wick has thinned so much there’s nothing left to hold the fire,” he said, when he finally got the fire to spread around.

From "Purple Hibiscus" by Chimamanda Ngozi Adichie

The car and truck commercials that once packed ad breaks are thinning out on traditional TV, particularly its cable networks, as automakers respond to intense budget pressure and consumers’ evolving media habits.

From The Wall Street Journal ● Oct. 27, 2026

Not long after beginning university, she started experiencing irregular and painful periods, thinning hair, weight gain and exhaustion.

From BBC ● Oct. 21, 2026

Forest Service, are overgrown because of decades of fire suppression, and that thinning them out through controlled burns would help reduce the amount of water absorbed by upland vegetation.

From Los Angeles Times ● Oct. 1, 2026

At this stage, high energy radiation from the young star can penetrate the thinning material and heat gas in the disk until it escapes.

From Science Daily ● Sep. 28, 2026

The campus crowd was already thinning out, and I didn’t want another teacher delaying my dinner any further with questions about why I’d lingered after the last recap.

From "Glitch" by Laura Martin

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Related Words

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