adjective, fat·ter, fat·test.


verb (used with or without object), fat·ted, fat·ting.

to make or become fat.


    a fat chance, Slang. a very slight chance; small probability: A fat chance he has of winning the title!
    a fat lot, Slang. little or not at all: A fat lot they care about anyone else's troubles!
    chew the fat. chew(def 11).
    the fat is in the fire,
    1. an irrevocable action or chain of events has been started; the die is cast: Now that they have been given an ultimatum, the fat is in the fire.
    2. the decision, whether good or bad, has been made.
    3. the crisis is imminent.
    the fat of the land, the best or richest of anything obtainable: to live on the fat of the land.

Origin of fat

before 1000; Middle English; Old English fǣtt, orig. past participle of fǣtan to cram, load, adorn; cognate with Gothic fētjan to adorn; akin to vat
Related formsfat·less, adjectivefat·like, adjectivede·fat, verb (used with object), de·fat·ted, de·fat·ting.o·ver·fat, adjectiveun·fat·ted, adjective
Can be confusedfat phat

Synonyms for fat

1. portly, adipose, pudgy. See stout. 3. unctuous, fatty. 4. lucrative, remunerative. 8. copious. 10. sluggish. 15. rich, fruitful, productive.

Antonyms for fat

1. thin. 3. lean. 10. clever. 15. sterile, barren.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for fat

Contemporary Examples of fat

Historical Examples of fat

British Dictionary definitions for fat



any of a class of naturally occurring soft greasy solids that are esters of glycerol and certain fatty acids. They are present in some plants and in the adipose tissue of animals, forming a reserve energy source, and are used in making soap and paint and in the food industrySee also oil (def. 1)
vegetable or animal tissue containing fatRelated adjectives: adipose, lipoid, stearic
corpulence, obesity, or plumpness
the best or richest part of something
a part in a play that gives an actor a good opportunity to show his talents
chew the fat slang
  1. to argue over a point
  2. to talk idly; gossip
the fat is in the fire an irrevocable action has been taken, esp one from which dire consequences are expected
the fat of the land the best that is obtainable

adjective fatter or fattest

having much or too much flesh or fat
consisting of or containing fat; greasyfat pork
profitable; lucrativea fat year
affording great opportunitiesa fat part in the play
fertile or productivea fat land
thick, broad, or extendeda fat log of wood
having a high content of a particular material or ingredient, such as resin in wood or oil in paint
plentifully supplieda fat larder
slang empty; stupidget this into your fat head
slang very little or none; minimal (in phrases such as a fat chance, a fat lot of good, etc)

verb fats, fatting or fatted

to make or become fat; fatten
Derived Formsfatless, adjectivefatlike, adjectivefatly, adverbfatness, nounfattish, adjective

Word Origin for fat

Old English fǣtt, past participle of fǣtan to cram; related to Old Norse feita, Old High German feizen to fatten; compare Gothic fētjan to adorn
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for fat

Old English fætt "fat, fatted, plump, obese," originally a contracted past participle of fættian "to cram, stuff," from Proto-Germanic *faitaz "fat" (cf. Old Frisian fatt, Old Norse feitr, Dutch vet, German feist), from PIE *poid- "to abound in water, milk, fat, etc." (cf. Greek piduein "to gush forth"), from root *peie- "to be fat, swell" (cf. Sanskrit payate "swells, exuberates," pituh "juice, sap, resin;" Lithuanian pienas "milk;" Greek pion "fat, wealthy;" Latin pinguis "fat").

Teen slang meaning "attractive, up to date" (also later phat) is attested from 1951. Fat cat "privileged and rich person" is from 1928; fat chance "no chance at all" attested from 1906. Fathead is from 1842; fat-witted is from 1590s; fatso is first recorded 1944. Expression the fat is in the fire originally meant "the plan has failed" (1560s).


mid-14c.; see fat (v.). Figurative sense of "best or most rewarding part" is from 1560s.

Online Etymology Dictionary, © 2010 Douglas Harper

Medicine definitions for fat




Any of various soft, solid, or semisolid organic compounds constituting the esters of glycerol and fatty acids and their associated organic groups.
A mixture of such compounds occurring widely in organic tissue, especially in the adipose tissue of animals and in the seeds, nuts, and fruits of plants.
Adipose tissue.
Obesity; corpulence.
Related formsfat adj.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

Science definitions for fat



Any of a large number of oily compounds that are widely found in plant and animal tissues and serve mainly as a reserve source of energy. In mammals, fat, or adipose tissue, is deposited beneath the skin and around the internal organs, where it also protects and insulates against heat loss. Fat is a necessary, efficient source of energy. An ounce of fat contains more than twice as much stored energy as does an ounce of protein or carbohydrates and is digested more slowly, resulting in the sensation of satiety after eating. It also enhances the taste, aroma, and texture of food. Fats are made chiefly of triglycerides, each molecule of which contains three fatty acids. Dietary fat supplies humans with essential fatty acids, such as linoleic acid and linolenic acid. Fat also regulates cholesterol metabolism and is a precursor of prostaglandins. See more at saturated fat unsaturated fat.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

Idioms and Phrases with fat


In addition to the idioms beginning with fat

  • fat cat
  • fat chance
  • fat city
  • fate worse than death, a
  • fat farm
  • fat is in the fire, the
  • fat lot
  • fat of the land, the

also see:

  • chew the fat
  • kill the fatted calf
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.