✨📕 The NEWThe NEW Collegiate Dictionary, 12th Edition Over 5,000 words added — Buy Now! Collegiate DictionaryBuy Now!

flatten

verb

flat·​ten ˈfla-tᵊn How to pronounce flatten (audio)
flattened; flattening ˈflat-niŋ How to pronounce flatten (audio)
ˈfla-tə-
Synonyms of flattennext

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 How to pronounce flatten (audio)
ˈfla-tə-
noun

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
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Young stars form within collapsing clouds of gas and dust, which flatten into broad protoplanetary disks where material gradually clumps into larger bodies. Samantha Mathewson, Space.com, 5 Dec. 2025 The Philadelphia Federal Reserve’s Beige Book in November documented an economy in decline, saying that hiring has flattened, warehouse workers are getting fewer hours on the job, inflationary pressures are coming from tariffs and sales of existing homes are decreasing. Josh Boak, Fortune, 4 Dec. 2025 Dart attempted to run the ball on a second down before ultimately getting flattened near the first down marker by New England linebacker Christian Elliss, in attempt to pick up a few extra yards. Skyler Caruso, PEOPLE, 3 Dec. 2025 Transfer the remaining purée to a freezer bag, flatten it and label and date the bag before freezing. Cody Godwin, USA Today, 1 Dec. 2025 See All Example Sentences for flatten

Word History

First Known Use

1630, in the meaning defined at transitive sense

Time Traveler
The first known use of flatten was in 1630

Cite this Entry

“Flatten.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/flatten. Accessed 8 Dec. 2025.

Kids Definition

flatten

verb
flat·​ten ˈflat-ᵊn How to pronounce flatten (audio)
flattened; flattening ˈflat-niŋ How to pronounce flatten (audio)
-ᵊn-iŋ
: to make or become flat

More from Merriam-Webster on flatten

Last Updated: - Updated example sentences
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!