to make flat.
to knock down: The boxer flattened his opponent in the second round.
to become flat.
flatten in, Nautical. flat1 (def. 61).
flatten out, Aeronautics. to fly into a horizontal position, as after a dive.
- flat·ten·er, noun
- o·ver·flat·ten, verb (used with object)
- un·flat·tened, adjective
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
How to use flatten in a sentence
He uses a spatula to flatten the onions and the meat together, creating a broad circular patty with an uneven edge.
They are specifically designed to ‘flatten out and mushroom’ when striking human tissue, and are intended to cause maximum damage.
In a way, the print emphasizes the pelt-like nature of all images, as they flatten out the world and hand it over to us.
And, when Fajr-5s began making them run for cover they did not began shouting to "flatten all of Gaza."
Recessions tend to flatten income differentials, but this Great Recession is having the opposite effect.
But I allow they'd flatten us all aout in jest abaout a minnit, if they wuz to set aout tew!Ramona | Helen Hunt Jackson
To do this it is necessary to slightly flatten all the fifths and sharpen the major thirds.The Recent Revolution in Organ Building | George Laing Miller
And then young Weedham tried a necktie tackle that was supposed to flatten Black Hood to the floor.
The strange thing about this Titanic machine is that it can crack an egg, or flatten out a ton or more of glowing iron.Steam Steel and Electricity | James W. Steele
Opposition may dissolve, antagonistic cults flatten out to a common culture, almost imperceptibly.The Outline of History: Being a Plain History of Life and Mankind | Herbert George Wells
British Dictionary definitions for flatten
(sometimes foll by out) to make or become flat or flatter
to knock down or injure; prostrate
to crush or subdue: failure will flatten his self-esteem
(tr) music to lower the pitch of (a note) by one chromatic semitone: Usual US word: flat
(intr foll by out) to manoeuvre an aircraft into horizontal flight, esp after a dive
- flattener, noun
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