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Synonyms

fatten

American  
[fat-n] / ˈfæt n /

verb (used with object)

  1. to make fat.

  2. to feed (animals) abundantly before slaughter.

  3. to enrich.

    to fatten the soil; to fatten one's pocketbook.

  4. Cards.

    1. Poker. to increase the number of chips in (a pot).

    2. Pinochle. to play a card that scores high on (a trick) expected to be taken by a partner.


verb (used without object)

  1. to grow fat.

fatten British  
/ ˈfætən /

verb

  1. to grow or cause to grow fat or fatter

  2. (tr) to cause (an animal or fowl) to become fat by feeding it

  3. (tr) to make fuller or richer

  4. (tr) to enrich (soil) by adding fertilizing agents

"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

Other Word Forms

  • fattenable adjective
  • fattener noun
  • fattening adjective
  • overfatten verb (used with object)

Etymology

Origin of fatten

First recorded in 1545–55; fat + -en 1

Explanation

To fatten someone is to feed them until they become bigger and fatter. Your grandmother might see a tiny baby and say, "His mother needs to fatten him up!" A farmer might spend weeks trying to fatten his prize pigs before he sells them for meat, and you may visit relatives who keep cooking you delicious food in an attempt to fatten you up. Figuratively, you can also fatten things like your bank account, by making it larger. Before the 1550s, the verb form of this word was fat — and both fat and fatten come from the Old English word fætt, "fat or plump."

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Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Soybean Export Council, a trade group, opened a Beijing office in 1982 to spread the word about protein-packed U.S. soybeans used to fatten livestock.

From The Wall Street Journal • Nov. 7, 2025

He was a skinny teenager told to go to buy milkshakes to "fatten him up".

From BBC • Nov. 7, 2025

Wilson’s phalaropes feed and fatten up at Mono Lake before their migration to South America.

From Los Angeles Times • Aug. 22, 2025

The Seahawks need to fatten up before staring down this quartet of stiff challenges: 49ers, Cowboys, 49ers, Eagles.

From Seattle Times • Nov. 17, 2023

If you could buy shoats on credit, fatten them on food that cost next to nothing, sell them, pay off your loan, and take your profit, you would really have done something.

From "East of Eden" by John Steinbeck