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

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.

Example Sentences

See Examples For:

thin thinner thinnest thins thinned thinning

But the Rams’ 16-0 halftime lead literally vanished into thin air.

From Los Angeles Times ● Sep. 28, 2026

Now it is a vulnerability, spreading its available air defenses thin across a landmass that is difficult to defend in its entirety.

From The Wall Street Journal ● Sep. 26, 2026

"In order to create those fractures, you have to have either a really thin ice on a really big ocean, or a higher eccentricity and a smaller ocean," Patthoff said.

From Science Daily ● Sep. 24, 2026

She slept in the cafe, her thin frame curled up in a red vinyl booth.

From Los Angeles Times ● Sep. 22, 2026

He’d never seen a variety quite like this before: thin, pale stems covered in wispy bands.

From "The Undead Fox of Deadwood Forest" by Aubrey Hartman

Ramirez’s two classmates, an Asian woman and a white man, remained in the edited version, but they were changed to appear thinner, and their facial features were noticeably distorted.

From Los Angeles Times ● Sep. 25, 2026

Much of the sea ice that remains today is younger and thinner than the multiyear ice that was once far more widespread across the Arctic Ocean.

From Science Daily ● Sep. 23, 2026

Under the ground and below the ocean’s surface lie millions of miles of glass strands thinner than a human hair.

From MarketWatch ● Sep. 19, 2026

Last September, the company pointed to a far thinner output, saying some 70,000 contributors had written 15,000 notes, only about six percent of which were published.

From Barron's ● Sep. 9, 2026

His hairline had receded slightly, and he looked thinner than I remembered him.

From "Mountains Beyond Mountains" by Tracy Kidder and Michael French

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

Lawyers said that part of his order seemed to be on the thinnest ice legally.

From The Wall Street Journal ● Mar. 6, 2026

The Angels’ minor league system is widely regarded as one of baseball’s thinnest.

From Los Angeles Times ● Nov. 11, 2025

Tats says I wear too many layers, so I choose my thinnest shirt made out of T-shirt material.

From "Saints and Misfits" by S.K. Ali

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

Molinari, though, benefited from one of the other effects of the weather: It thins out the rough.

From The Wall Street Journal ● Jul. 15, 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

Because the ice shell on Mimas is not expected to fracture as it thins, it is possible for the moon to have an ocean while still looking inactive at the surface.

From Science Daily ● Mar. 2, 2026

He stops at a corner beneath the awning of a café, watching the lamps flickering on up and down the street, wondering if he should wait until the crowd thins or the rain lets up.

From "The Night Circus" by Erin Morgenstern

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

"Practices will need to be incentivised back into NHS work in the places where the NHS footprint has thinned most."

From BBC ● Aug. 23, 2026

Within minutes the crowds thinned, leaving long stretches of sand with barely another beachgoer in sight.

From The Wall Street Journal ● Aug. 17, 2026

And as the 2023 dual writers’ and actors’ strikes thinned out theatrical lineups, that aversion to uncertainty became a push for reliable and profitable hits.

From Los Angeles Times ● Jul. 1, 2026

When Luna walked with her grandmother in the opposite direction, eventually the trees thinned and gave way to farms, and the farms gave way to towns, which gave way to more farms.

From "The Girl Who Drank the Moon" by Kelly Barnhill

Staff will continue regular inspections to detect crown thinning, needle discoloration and loss, reduced growth and abnormal resin production, she said.

From Los Angeles Times ● Sep. 19, 2026

The chart below shows the thinning gap between annualized inflation rates and APYs.

From MarketWatch ● Sep. 14, 2026

Festivals and fairs crowd the calendar through summer and fall, thinning out but never disappearing entirely once the weather turns cold.

From Salon ● Sep. 8, 2026

"This is a timely study given the history of fire suppression in these forests and the state's increasing pace and scale of fuel thinning in recent years," Jin said.

From Science Daily ● Jul. 26, 2026

The abbot’s eyebrows now nearly mingled with his thinning hair.

From "The Inquisitor's Tale" by Adam Gidwitz

Related Words

• delicate
• fragile
• gaunt
• lean
• meager
• narrow
• skinny
• slim
• small