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.

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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

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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."

Example Sentences

They are sold to feedlots that fatten them up before being shipped to slaughterhouses.

From The Wall Street Journal • Apr. 20, 2026

Instead, the company said, the measure is aimed at tackling a perennial problem in California’s legal system: attorneys pushing car crash victims into expensive surgeries in order to fatten their fees.

From Los Angeles Times • Jan. 17, 2026

Mountain goats deal with heavy snow, and have a short window of time to fatten up before the thick of winter.

From Seattle Times • May 22, 2024

Liz Truss told the Institute for Government she tried to rear, fatten and slaughter a pig on market day in her rush to meet voters' need for change saying she had "limited time".

From BBC • Sep. 18, 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

Related Words

• augment
• broaden
• build up
• swell