flatten

verb

flat·​ten ˈfla-tᵊn 

flattened; flattening ˈflat-niŋ 

ˈfla-tə-

transitive verb

: to make flat

flatten the dough into a disk

The dog flattened its ears.

: such as

a

: to make level or smooth

flattened the papers

b

: to knock down

houses flattened by the tornado

also : to defeat decisively

got flattened in the first round of playoffs

c

: to make dull or uninspired

… small changes … that flatten a writer's style …

—John Gross

—often used with out

In thus flattening out a complicated story, the book misses an opportunity …

—Tony Judt

d

: to make lusterless

flatten paint

e

: to stabilize especially at a lower level

a candidate promising to flatten interest rates

intransitive verb

: to become flat or flatter: such as

a

: to become dull or spiritless

b

: to extend in or into a flat position or form

c

: to become uniform or stabilized often at a new lower level

—usually used with out

prices flattening out

flattener

ˈflat-nər 

ˈfla-tə-

noun

Synonyms of flatten

• smooth

Examples of flatten in a Sentence

Dozens of houses were flattened by the tornado.

The boxer was flattened in the seventh round.

The team got flattened in the first round of the play-offs.

Prices are expected to flatten after the holiday shopping season.

Recent Examples on the Web

The org chart flattens because the coordination overhead that justified middle layers, translating between product, builders, and reviewers, is increasingly absorbed by AI tools. — Michael Wee, Forbes.com, 3 Aug. 2026

This occurs when extreme bending forces from wind, waves, or earthquakes cause a hollow steel tower to lose its circular shape and flatten into an oval. — Mrigakshi Dixit, Interesting Engineering, 31 July 2026

Political debates have a way of flattening complicated issues that on-the-ground reporting rarely does. — Jamie Stockwell, USA Today, 31 July 2026

But the necessity of paring down such a massive event has the effect of flattening the very elements that ought to give it its texture and heft — namely, the people involved. — Angie Han, HollywoodReporter, 30 July 2026

Word History

First Known Use

1630, in the meaning defined at transitive sense

Rhymes for flatten

• batten
• craton
• fatten
• gratin
• gratton
• latin
• lattin
• matin
• paten
• patten
• platen
• ratan

Kids Definition

flatten

verb

flat·​ten ˈflat-ᵊn 

flattened; flattening ˈflat-niŋ 

-ᵊn-iŋ

: to make or become flat