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.

---

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

---

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

---

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 timeline for election administrators to think through the issue before November is tight, and it poses challenges for offices that already are stretched thin preparing for other possible election-day scenarios.

From Los Angeles Times ● Aug. 12, 2026

With so many staffers leaving and not being replaced, the remaining providers have often been stretched remarkably thin.

From Salon ● Aug. 12, 2026

And just above the visible surface sits a thin, pinkish layer called the chromosphere - only a few thousand kilometres thick.

From BBC ● Aug. 11, 2026

Yet for a few hours, a thin and arbitrary strip of the planet becomes its most desirable real estate.

From The Wall Street Journal ● Aug. 10, 2026

I put my hand on his shoulder and patted his thin back.

From "Nory Ryan’s Song" by Patricia Reilly Giff

The completed structure is also thinner than a human hair.

From Science Daily ● Aug. 8, 2026

Structural outflows from households buying foreign equities and thinner corporate profit repatriation will weigh too.

From The Wall Street Journal ● Aug. 4, 2026

Analysts said generic-drug makers operate on thinner margins than manufacturers of branded medicines and might struggle to move production to the U.S. due to pricing pressures.

From The Wall Street Journal ● Jul. 22, 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

The trees were thinner now, less like the trees of giants.

From "Breadcrumbs" by Anne Ursu

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

The thinnest part of the phone, the left-side panel, is 3.9 millimeters thick—equivalent to five credit cards—and the device is 12.9 millimeters thick when completely folded.

From The Wall Street Journal ● Dec. 2, 2025

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

From Los Angeles Times ● Nov. 11, 2025

I was fascinated by how he could direct the thinnest, most even spray of water from his mouth onto the clothes he was pressing.

From "The Boy on the Wooden Box" by Leon Leyson

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

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

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

Despite her care, Javier’s skin turns sallow and thins until it looks as if she could strip it away in papery sheets.

From "Dreaming in Cuban" by Cristina García

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

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

From Science Daily ● Jul. 20, 2026

The 37-year-old responded with back-to-back birdies, but a thinned chip on the 15th which ran into a bunker, contributed to a double-bogey six.

From BBC ● Jun. 20, 2026

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

But by late morning, the ash had thinned somewhat.

From "Mountain of Fire" by Rebecca E. F. Barone

"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

Miguez, who has rocked the look himself since 2018, said that men often look younger with buzzed heads than with visibly thinning hair.

From The Wall Street Journal ● Jun. 24, 2026

Earlier research has raised concerns that rapid weight loss associated with GLP-1 medications may contribute to bone thinning and increase fracture risk.

From Science Daily ● Jun. 16, 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

He had a thick body, heavy shoulders, a long, bony face, and thinning hair.

From "Lupita Mañana" by Patricia Beatty

Related Words

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