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 staff in Salisbury also say missed appointments, whether down to late letters, illness, transport problems or anxiety, are a constant drain on a system already stretched thin.

From BBC ● Sep. 10, 2026

Families searched for missing loved ones long after hope had become terribly thin.

From Salon ● Sep. 8, 2026

Hortiz doesn’t want the Chargers, who devastatingly lost starting center Tyler Biadasz to a season-ending anterior cruciate ligament injury, to be as thin on the offensive line as they were in 2025.

From Los Angeles Times ● Sep. 7, 2026

He tried a different Starbucks in the Washington, D.C.-area, but his order still came out thin and bland.

From The Wall Street Journal ● Sep. 4, 2026

She was dangerously thin, I felt, for an expectant mother, and several times I brought her a portion of my own breakfast bread.

From "The Hiding Place" by Corrie ten Boom

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

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

Now she could see that he was younger than she’d thought, perhaps only in his thirties, and thinner, too.

From "Little Fires Everywhere" by Celeste Ng

The model represents the company’s largest change yet to its iconic line of mobile phones, and is the thinnest iPhone to date when unfolded, Apple says at its fall product showcase.

From The Wall Street Journal ● Sep. 10, 2026

“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

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 second hand, the thinnest of the three, suddenly snapped and fell out of the clockface completely, bouncing once on the rug and disappearing into the ashes of the hearth.

From "A Monster Calls" by Patrick Ness

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

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

From Science Daily ● Nov. 13, 2025

She has keratoconus - a condition where the cornea thins and bulges, causing distorted and blurred vision.

From BBC ● Oct. 18, 2024

At thirty weeks her skin thins, and her hair gets thicker.

From "Middlesex: A Novel" by Jeffrey Eugenides

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

"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

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

From Science Daily ● Jul. 20, 2026

The tall trees thinned out, bush and undergrowth were sparse.

From "Redwall" by Brian Jacques

Indianapolis lost Michael Pittman Jr. to Pittsburgh in the offseason, thinning out the passing game.

From Los Angeles Times ● Sep. 9, 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

An Arkansas thinning cost him $1.50 a ton.

From The Wall Street Journal ● Aug. 28, 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

One of the guards, an aging man with thinning hair, saluted a second time and said, “Captain—you’re needed.”

From "Throne of Glass" by Sarah J. Maas

Related Words

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