flatten

1 of 2

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

flattener

2 of 2

noun

flat·​ten·​er ˈflat(ᵊ)nə(r) 

plural -s

: one that flattens: such as

a

: a worker who flattens materials (as metal, leather, paper, or glass)

b

: a machine for flattening or straightening plates or sheets

Synonyms of flatten

Verb

• smooth

Examples of flatten in a Sentence

Verb

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

Verb

Companies that invest only in capturing demand often find their pipeline is fragile, their cost per acquisition climbs over time and growth flattens once the in-market segment is saturated. — James Fratzke, Forbes.com, 26 June 2026

Water the soil lightly to not flatten your mound. — Ashlyn Needham, Southern Living, 26 June 2026

The widespread destruction in Venezuela — with more than 900 dead and countless structures flattened — is expected to focus more attention on the seismic phenomenon and how to make buildings and infrastructure more resilient. — Los Angeles Times, 26 June 2026

The date was chosen to coincide with the anniversary of the Tunguska impact of 1908, when an asteroid exploded over Siberia, flattening millions of trees in an 830 square mile (2,148 sq km) area. — Anthony Wood, Space.com, 26 June 2026

Word History

First Known Use

Verb

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