Merriam-Webster Logo
  • Dictionary
  • Thesaurus
  • Medical
  • Scrabble
  • Spanish Central
  • Learner's Dictionary


adjective \ˈthin\

Simple Definition of thin

  • : having a small distance between the top and bottom or front and back surfaces : not thick

  • : not having a lot of extra flesh on the body : not fat

  • : not growing closely together : not growing in a large amount

Full Definition of thin


  1. 1a :  having little extent from one surface to its opposite <thin paper>b :  measuring little in cross section or diameter <thin rope>

  2. 2 :  not dense in arrangement or distribution <thin hair>

  3. 3 :  not well fleshed :  lean

  4. 4a :  more fluid or rarefied than normal <thin air>b :  having less than the usual number :  scanty <thin attendance>c :  few in number :  scarced :  scantily suppliede :  characterized by a paucity of bids or offerings <a thin market>

  5. 5a :  lacking substance or strength <thin broth> <a thin plot>b of a soil :  infertile, poor

  6. 6a :  flimsy, unconvincing <a thin disguise>b :  disappointingly poor or hard <had a thin time of it>

  7. 7 :  somewhat feeble, shrill, and lacking in resonance <a thin voice>

  8. 8 :  lacking in intensity or brilliance <thin light>

  9. 9 :  lacking sufficient photographic density or contrast

thin·ly adverb
thin·ness play \ˈthin-nəs\ noun
thin·nish play \ˈthi-nish\ adjective
thin on the ground
  1. :  scarce 1

Examples of thin

  1. a thin coating of dust

  2. pizza with a thin crust

  3. a thin slice of ham

  4. a thin stand of trees

Origin of thin

Middle English thinne, from Old English thynne; akin to Old High German dunni thin, Latin tenuis thin, tenēre to hold, tendere to stretch, Greek teinein

First Known Use: before 12th century

Synonym Discussion of thin

thin, slender, slim, slight, tenuous mean not thick, broad, abundant, or dense. thin implies comparatively little extension between surfaces or in diameter, or it may imply lack of substance, richness, or abundance <thin wire> <a thin soup>. slender implies leanness or spareness often with grace and good proportion <the slender legs of a Sheraton chair>. slim applies to slenderness that suggests fragility or scantiness <a slim volume of poetry> <a slim chance>. slight implies smallness as well as thinness <a slight build>. tenuous implies extreme thinness, sheerness, or lack of substance and firmness <a tenuous thread>.

Rhymes with thin




Simple Definition of thin

  • : to become less crowded, close together, or full

  • : to make (a liquid) less thick by adding water or some other liquid to it

  • of a person's hair : to become less thick as more hairs fall out over time

Full Definition of thin


  1. transitive verb
  2. :  to make thin or thinner:a :  to reduce in thickness or depth :  attenuateb :  to make less dense or viscousc :  dilute, weakend :  to cause to lose flesh <thinned by weeks of privation>e :  to reduce in number or bulk

  3. intransitive verb
  4. 1 :  to become thin or thinner

  5. 2 :  to become weak

Examples of thin

  1. He added a little more water to thin the gravy.

  2. The haze thinned in the late afternoon.

  3. His face has been thinned by illness.

Before 12th Century

First Known Use of thin

before 12th century




Simple Definition of thin

  • : in a way that makes thin pieces, layers, etc.

Full Definition of thin


  1. :  in a thin manner :  thinly —used especially in combination <thin-clad> <thin-flowing>

Examples of thin

  1. She sliced the cheese thin.

13th Century

First Known Use of thin

13th century

Seen and Heard

What made you want to look up thin? Please tell us where you read or heard it (including the quote, if possible).


February 11, 2016

the holder of an office

Get Word of the Day daily email!


Take a 3-minute break and test your skills!


How much does a batman (the Turkish unit of measurement) weigh?

2.2 pounds 100 pounds 16.96 pounds 196.5 pounds
Name That Thing

10 quick questions: hear them, spell them, and see how your skills compare to the crowd.


Test Your Knowledge - and learn some interesting things along the way.