flatten

[ flat-n ]
See synonyms for flatten on Thesaurus.com
verb (used with object)
  1. to make flat.

  2. to knock down: The boxer flattened his opponent in the second round.

verb (used without object)
  1. to become flat.

Verb Phrases
  1. flatten in, Nautical. flat1 (def. 61).

  2. flatten out, Aeronautics. to fly into a horizontal position, as after a dive.

Origin of flatten

1
First recorded in 1620–30; flat1 + -en1

Other words for flatten

Other words from flatten

  • 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. 2024

How to use flatten in a sentence

  • The region of the head first becomes distinguishable by the flattening out of the germ at its front end.

  • Flattening out just in time to avert destruction it taxied up the field almost to the house.

    The Skylark of Space | Edward Elmer Smith and Lee Hawkins Garby
  • These special cushions keep the body from flattening out, as it normally would under such a pressure.

    The Skylark of Space | Edward Elmer Smith and Lee Hawkins Garby
  • Do not make the hat too flat; if you find it flattening out, lap the leaves over more at the bottom.

  • Joan reached the corridor just in time to see the elevator flattening out its iron gates with judge and briefcase inside.

    Joan of the Journal | Helen Diehl Olds

British Dictionary definitions for flatten

flatten

/ (ˈflætən) /


verb
  1. (sometimes foll by out) to make or become flat or flatter

  2. (tr) informal

    • to knock down or injure; prostrate

    • to crush or subdue: failure will flatten his self-esteem

  1. (tr) music to lower the pitch of (a note) by one chromatic semitone: Usual US word: flat

  2. (intr foll by out) to manoeuvre an aircraft into horizontal flight, esp after a dive

Derived forms of flatten

  • 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