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

They need to be cherished for their loyalty and focus on their grandkids, through thick and thin.

From Los Angeles Times ● Oct. 21, 2026

At night, they slept in bunk beds with only plastic sheeting over the mattress, and one very thin blanket.

From BBC ● Oct. 19, 2026

When the knife fell flat across the basket, the robot’s hands had difficulty grabbing the thin piece of metal.

From MarketWatch ● Oct. 16, 2026

Until now, directing their movement in extremely thin, two-dimensional superconductors has been particularly difficult.

From Science Daily ● Oct. 16, 2026

It was not coffee but a thin liquid of approximately the same color, and we were grateful to get it as we shuffled double-file past the makeshift field kitchen.

From "The Hiding Place" by Corrie ten Boom

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

But where the evidence is thinner, AI could help us examine what we’re experiencing, consider alternative meanings, and decide for ourselves what to carry forward and how to act on it.

From The Wall Street Journal ● Sep. 27, 2026

I’m thinner than I was a year ago.

From "Atonement" by Ian McEwan

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

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

From Los Angeles Times ● Nov. 11, 2025

“Congratulations!” he exclaimed bitterly, the thinnest milk- white line enclosing his lips tightly in a bloodless, squeezing ring.

From "Catch-22" by Joseph Heller

What’s more, staying hydrated helps flush toxins, keeps organs functioning optimally and thins mucus, making it easier for lungs to stay clear.

From The Wall Street Journal ● Jul. 23, 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

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

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

As I thinned out the garage shelves—recycling old paint, giving away a box of used electric outlets, listing plumbing supplies on Craigslist’s “free stuff” section—the shelves grew neater.

From The Wall Street Journal ● Aug. 8, 2026

They can detect fibers that have thinned, broken apart, or lost their connections.

From Science Daily ● Jul. 20, 2026

When she saw Kaz, her lips thinned to a sour line, and she lifted her glass, the gesture more threat than toast.

From "Six of Crows" by Leigh Bardugo

An outer buffer that slows wildfires by thinning trees, clearing dead brush, and breaking up continuous vegetation.

From The Wall Street Journal ● Oct. 21, 2026

The trees left behind after thinning were enormous.

From Science Daily ● Oct. 4, 2026

But scientists say long-term glacier thinning and the thawing of frozen ground likely raised the risks.

From BBC ● Oct. 1, 2026

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 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

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

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