Nearby words

  1. flashpoint,
  2. flashtube,
  3. flashy,
  4. flask,
  5. flasket,
  6. flat arch,
  7. flat as a pancake,
  8. flat back,
  9. flat bond,
  10. flat bone


Origin of flat

1275–1325; Middle English < Old Norse flatr, akin to Old English flet (see flat2), Greek platýs (see platy-, plate1

1. plane. See level. 4. low, prone. 11. outright, peremptory, categorical. 14. boring, spiritless, prosaic. 17. vapid, unsavory.

Related formsflat·ly, adverbflat·ness, nounun·flat·ted, adjective Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for flatness

British Dictionary definitions for flatness



adjective flatter or flattest

horizontal; levelflat ground; a flat roof
even or smooth, without projections or depressionsa flat surface
lying stretched out at full length; prostratehe lay flat on the ground
having little depth or thickness; shallowa flat dish
(postpositive often foll by against) having a surface or side in complete contact with another surfaceflat against the wall
spread out, unrolled, or levelled
(of a tyre) deflated, either partially or completely
(of shoes) having an unraised or only slightly raised heel
mainly British
  1. (of races, racetracks, or racecourses) not having obstacles to be jumped
  2. of, relating to, or connected with flat racing as opposed to steeplechasing and hurdlingflat jockeys earn more
without qualification; totala flat denial
without possibility of change; fixeda flat rate
(prenominal or immediately postpositive) neither more nor less; exacthe did the journey in thirty minutes flat; a flat thirty minutes
unexciting or lacking point or interesta flat joke
without variation or resonance; monotonousa flat voice
(of food) stale or tasteless
(of beer, sparkling wines, etc) having lost effervescence, as by exposure to air
(of trade, business, a market, etc) commercially inactive; sluggish
(of a battery) fully discharged; dead
(of a print, photograph, or painting) lacking contrast or shading between tones
(of paint) without gloss or lustre; matt
(of a painting) lacking perspective
(of lighting) diffuse
  1. (immediately postpositive)denoting a note of a given letter name (or the sound it represents) that has been lowered in pitch by one chromatic semitoneB flat
  2. (of an instrument, voice, etc) out of tune by being too low in pitchCompare sharp (def. 12)
phonetics another word for lenis
flat a phonetics the vowel sound of a as in the usual US or S Brit pronunciation of hand, cat, usually represented by the symbol (æ)


in or into a prostrate, level, or flat state or positionhe held his hand out flat
completely or utterly; absolutelyhe went flat against the rules
exactly; preciselyin three minutes flat
  1. lower than a standard pitch
  2. too low in pitchshe sings flat Compare sharp (def. 18)
fall flat to fail to achieve a desired effect, etc
flat out informal
  1. with the maximum speed or effort
  2. totally exhausted


a flat object, surface, or part
(often plural) a low-lying tract of land, esp a marsh or swamp
(often plural) a mud bank exposed at low tide
  1. an accidental that lowers the pitch of the following note by one chromatic semitoneUsual symbol:
  2. a note affected by this accidentalCompare sharp (def. 19)
theatre a rectangular wooden frame covered with painted canvas, etc, used to form part of a stage setting
a punctured car tyre
the flat mainly British ((often cap.))
  1. flat racing, esp as opposed to steeplechasing and hurdling
  2. the season of flat racing
nautical a flatboat or lighter
US and Canadian a shallow box or container, used for holding plants, growing seedlings, etc

verb flats, flatting or flatted

to make or become flat
music the usual US word for flatten (def. 3)
See also flats

Derived Formsflatly, adverbflatness, noun

Word Origin for flat

C14: from Old Norse flatr; related to Old High German flaz flat, Greek platus flat, broad




a set of rooms comprising a residence entirely on one floor of a buildingUsual US and Canadian name: apartment
British and NZ a portion of a house used as separate living quarters
NZ a house shared with people who are not members of one's own family

verb flats, flatting or flatted (intr)

Australian and NZ to live in a flat (with someone)

Word Origin for flat

Old English flett floor, hall, house; related to flat 1

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

Word Origin and History for flatness
Online Etymology Dictionary, © 2010 Douglas Harper

Idioms and Phrases with flatness


In addition to the idioms beginning with flat

  • flat as a pancake
  • flat broke
  • flat on one's back
  • flat out

also see:

  • caught flat-footed
  • fall flat
  • in no time (nothing flat)
  • leave flat
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.