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

The researchers next added thin conductive yarns to demonstrate how the technology could be used in practical devices.

From Science Daily ● Sep. 4, 2026

When her bandages are unwrapped, she’s devastated to learn that her face is still symmetrical, with a thin nose, unblemished skin, and full lips.

From Slate ● Sep. 2, 2026

One wrote on X that the 33-year-old had "become so thin that people are genuinely concerned".

From BBC ● Sep. 1, 2026

She recalls how for years she had lived in “that thin upper surface of comfort and joy and freedom” that the bohemian life made possible.

From The Wall Street Journal ● Aug. 31, 2026

Her grip on my knee stiffens and her mouth freezes into a thin line.

From "Red Flags and Butterflies" by Sheryl Azzam

Then, on Tuesday, I got a photo of her in a hospital bed, and I cried because I guess I hadn’t realized she could get thinner.

From Salon ● Aug. 31, 2026

Yields are expected to fall, while thinner cane with lower sucrose content means less sugar can be produced.

From BBC ● Aug. 26, 2026

When the researchers made the polymer film thinner, many small polymer aggregates appeared across the surface.

From Science Daily ● Aug. 23, 2026

They deliver thinner margins, but capture a corner of the market GM left.

From The Wall Street Journal ● Aug. 21, 2026

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

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

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

But it’ll be even more vital in the postseason, when the margin for error is at its thinnest.

From Los Angeles Times ● Jul. 3, 2026

Value is concentrated exactly where capacity is thinnest.

From MarketWatch ● Jul. 1, 2026

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

From The Wall Street Journal ● Mar. 6, 2026

It was Professor McGonagall, and her mouth was the thinnest of thin lines.

From "Harry Potter And The Chamber Of Secrets" by J. K. Rowling

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

As the remaining ice thins and retreats, more open ocean is left exposed to sunlight.

From Science Daily ● Nov. 13, 2025

As the infrastructure thins out the further you travel, roads are replaced by dirt tracks created by the few vehicles that pass.

From BBC ● Mar. 22, 2025

She felt small and fragile, the way ice over a lake thins as the weather turns warm.

From "We Are the Ants" by Shaun David Hutchinson

I’ve thinned out my closet mostly to clothes, shoes and luggage I use during a year’s time.

From The Wall Street Journal ● Aug. 8, 2026

His once thick black hair has greyed and thinned, much like his trademark beard.

From Barron's ● Aug. 2, 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

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

The crowd thinned and they were able to climb the next staircase without difficulty.

From "Harry Potter And The Chamber Of Secrets" by J. K. Rowling

Howard is planting fewer seedlings per acre to reduce upfront costs and thinning.

From The Wall Street Journal ● Aug. 28, 2026

An Arkansas thinning cost him $1.50 a ton.

From The Wall Street Journal ● Aug. 28, 2026

Last month, when pressed on the subject, Hegseth denied that supplies were thinning out.

From BBC ● Jul. 27, 2026

"Unlike Californian forests, where preventative measures can be taken through thinning, boreal forests, which are very dense, cannot be controlled," Bergeron said.

From Barron's ● Jul. 20, 2026

Do you know how many blocks there were before the houses started thinning out after the library?

From "Okay for Now" by Gary D. Schmidt

Related Words

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