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adjective \ˈfat\

Simple Definition of fat

  • : having a lot of extra flesh on your body : having a lot of body fat

  • : having a full, rounded form

  • : unusually wide or thick

Full Definition of fat


  1. 1 :  notable for having an unusual amount of fat: a :  plump b :  obese c of a meat animal :  fattened for market d of food :  oily, greasy

  2. 2 a :  well filled out :  thick, big <a fat book> b :  full in tone and quality :  rich <a gorgeous fat bass voice — Irish Digest> c :  well stocked <a fat larder> d :  prosperous, wealthy <grew fat on the war — Time> e :  being substantial and impressive <a fat bank account>

  3. 3 a :  richly rewarding or profitable <a fat part in a movie> <a fat contract> b :  practically nonexistent <a fat chance>

  4. 4 :  productive, fertile <a fat year for crops>

  5. 5 :  stupid, foolish

  6. 6 :  being swollen <got a fat lip from the fight>

  7. 7 of a baseball pitch :  easy to hit

fat·ness noun

Examples of fat

  1. The dog is getting fat because you feed him too much.

  2. I can't believe I've let myself get so fat.

  3. a fat book of poems

  4. a truck with fat tires

Origin of fat

Middle English, from Old English fǣtt, past participle of fǣtan to cram; akin to Old High German feizit fat

First Known Use: before 12th century




Definition of fat


  1. transitive verb
  2. :  to make fat :  fatten

Before 12th Century

First Known Use of fat

before 12th century




Simple Definition of fat

  • : the soft flesh on the bodies of people and animals that helps keep the body warm and is used to store energy

  • : an oily solid or liquid substance in food

  • : an amount that is more than what is usual or needed

Full Definition of fat

  1. 1 :  animal tissue consisting chiefly of cells distended with greasy or oily matter

  2. 2 a :  oily or greasy matter making up the bulk of adipose tissue and often abundant in seeds b :  any of various compounds of carbon, hydrogen, and oxygen that are glycerides of fatty acids, are the chief constituents of plant and animal fat, are a major class of energy-rich food, and are soluble in organic solvents but not in water c :  a solid or semisolid fat as distinguished from an oil

  3. 3 :  the best or richest part

  4. 4 :  obesity

  5. 5 :  something in excess :  superfluity <trim the fat from the news operation — Ray Olson>

fat·less play \-ləs\ adjective

Examples of fat

  1. people with excess body fat

  2. a diet and exercise program to help you gain muscle and lose fat

  3. Nuts contain a lot of fat.

  4. Trim the fat from the meat before you cook it.

  5. a diet low in fats

  6. fats like butter and olive oil

  7. trim the fat off the budget

14th Century

First Known Use of fat

14th century

Other Biochemistry Terms

Seen and Heard

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


February 12, 2016

of, relating to, or suggestive of marble

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