verb (used with object)
to make flat.
to knock down: The boxer flattened his opponent in the second round.
verb (used without object)
to become flat.
flatten in, Nautical. flat1(def 61).
flatten out, Aeronautics. to fly into a horizontal position, as after a dive.
Origin of flatten
Synonyms for flatten
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
(sometimes foll by out) to make or become flat or flatter
- to knock down or injure; prostrate
- to crush or subduefailure will flatten his self-esteem
(tr) music to lower the pitch of (a note) by one chromatic semitoneUsual US word: flat
(intr foll by out) to manoeuvre an aircraft into horizontal flight, esp after a dive
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
Online Etymology Dictionary, © 2010 Douglas Harper