View synonyms for flat



[ flat ]


, flat·ter, flat·test.
  1. horizontally level:

    a flat roof.

    Synonyms: plane

  2. level, even, or without unevenness of surface, as land or tabletops.
  3. having a surface that is without marked projections or depressions:

    a broad, flat face.

  4. lying horizontally and at full length, as a person; prostrate:

    He was flat on the canvas after the knockdown.

    Synonyms: prone, low

    Antonyms: vertical, upright

  5. lying wholly on or against something:

    The banner was flat against the wall.

  6. thrown down, laid low, or level with the ground, as fallen trees or buildings.
  7. having a generally level shape or appearance; not deep or thick:

    a flat plate.

  8. (of the heel of a shoe) low and broad.
  9. spread out, as an unrolled map or the open hand.
  10. deflated; collapsed:

    a flat tire.

  11. absolute, downright, or positive; without qualification:

    a flat denial.

    Synonyms: categorical, peremptory, outright

  12. without modification or variation:

    a flat rate.

  13. Informal. lacking money; broke.
  14. without vitality or animation; lifeless; dull:

    flat writing.

    Synonyms: prosaic, spiritless, boring

    Antonyms: spirited

  15. having lost its flavor, sharpness, or life, as wine or food; stale.
  16. (of a beverage) having lost its effervescence.
  17. without flavor; not spiced:

    flat cooking.

    Synonyms: unsavory, vapid

    Antonyms: savory, flavorful

  18. prosaic, banal, or insipid:

    a flat style.

  19. pointless, as a remark or joke.
  20. commercially inactive:

    a flat day in the stock market.

  21. (of a painting) not having the illusion of volume or depth.
  22. (of a photograph or painting) lacking contrast or gradations of tone or color.
  23. (of paint) without gloss; not shiny; mat.
  24. not clear, sharp, or ringing, as sound or a voice.
  25. lacking resonance and variation in pitch; monotonous:

    a flat delivery of the speech.

  26. Music.
    1. (of a tone) lowered a half step in pitch:

      B flat.

    2. below an intended pitch, as a note; too low ( sharp ).
  27. Grammar. derived without change in form, as English to brush from the noun brush and adverbs that do not add -ly to the adjective form as fast, cheap, and slow.
  28. Phonetics. lenis; voiced.
  29. Nautical. (of a sail)
    1. cut with little or no fullness.
    2. trimmed as nearly fore-and-aft as possible, for sailing to windward.
  30. flat a, the a -sound (a) of glad, bat, or act.


  1. something flat.
  2. a shoe, especially a woman's shoe, with a flat heel or no heel.
  3. a flat surface, side, or part of anything:

    He struck me with the flat of his hand.

  4. flat or level ground; a flat area:

    salt flats.

  5. a marsh, shoal, or shallow.
  6. Music.
    1. (in musical notation) the character ♭, which when attached to a note or to a staff degree lowers its significance one chromatic half step.
    2. a tone one chromatic half step below another:

      The flat of B is B flat.

    3. (on keyboard instruments, with reference to any given note) the key next below or to the left.
  7. Theater. a piece of scenery consisting of a wooden frame, usually rectangular, covered with lightweight board or fabric.
  8. a broad, thin book, chiefly for children:

    a juvenile flat.

  9. Informal. a deflated automobile tire.
  10. (in postal use) a large flat package, as in a manila envelope, for mailing.
  11. Architecture. a flat roof or deck.
  12. Nautical.
    1. Also called platform. a partial deck between two full decks.
    2. a low, flat barge or lighter.
  13. Shipbuilding.
    1. a broad, flat piece of iron or steel for overlapping and joining two plates at their edges.
    2. a straight timber in a frame or other assembly of generally curved timbers.
  14. an iron or steel bar of rectangular cross section.
  15. Textiles. one of a series of laths covered with card clothing, used in conjunction with the cylinder in carding.
  16. Photography. one or more negatives or positives in position to be reproduced.
  17. Printing. a device for holding a negative or positive flat for reproduction by photoengraving.
  18. Horticulture. a shallow, lidless box or tray used for rooting seeds and cuttings and for growing young plants.
  19. a similar box used for shipping and selling fruits and vegetables.
  20. Football. the area of the field immediately inside of or outside of an offensive end, close behind or at the line of scrimmage.
  21. flats, Informal. flat races between horses. Compare flat race ( def ).

verb (used with object)

, flat·ted, flat·ting.
  1. to make flat.
  2. Music. to lower (a pitch), especially one half step.

verb (used without object)

, flat·ted, flat·ting.
  1. to become flat.


  1. in a flat position; horizontally; levelly.
  2. in a flat manner; positively; absolutely.
  3. completely; utterly:

    flat broke.

  4. exactly; precisely:

    She ran around the track in two minutes flat.

  5. Music. below the true pitch:

    to sing flat.

  6. Finance. without interest.

verb phrase

  1. Nautical. to pull the clew of (a fore-and-aft sail) as nearly amidships as possible. Also flatten in.



[ flat ]


, Chiefly British.
  1. an apartment or suite of rooms on one floor forming a residence.



/ flæt /


  1. horizontal; level

    flat ground

    a flat roof

  2. even or smooth, without projections or depressions

    a flat surface

  3. lying stretched out at full length; prostrate

    he lay flat on the ground

  4. having little depth or thickness; shallow

    a flat dish

  5. postpositiveoften foll byagainst having a surface or side in complete contact with another surface

    flat against the wall

  6. spread out, unrolled, or levelled
  7. (of a tyre) deflated, either partially or completely
  8. (of shoes) having an unraised or only slightly raised heel
    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 hurdling

      flat jockeys earn more

  9. without qualification; total

    a flat denial

  10. without possibility of change; fixed

    a flat rate

  11. prenominal or immediately postpositive neither more nor less; exact

    a flat thirty minutes

    he did the journey in thirty minutes flat

  12. unexciting or lacking point or interest

    a flat joke

  13. without variation or resonance; monotonous

    a flat voice

  14. (of food) stale or tasteless
  15. (of beer, sparkling wines, etc) having lost effervescence, as by exposure to air
  16. (of trade, business, a market, etc) commercially inactive; sluggish
  17. (of a battery) fully discharged; dead
  18. (of a print, photograph, or painting) lacking contrast or shading between tones
  19. (of paint) without gloss or lustre; matt
  20. (of a painting) lacking perspective
  21. (of lighting) diffuse
  22. music
    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 semitone

      B flat

    2. (of an instrument, voice, etc) out of tune by being too low in pitch Compare sharp
  23. phonetics another word for lenis
  24. 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)


  1. in or into a prostrate, level, or flat state or position

    he held his hand out flat

  2. completely or utterly; absolutely

    he went flat against the rules

  3. exactly; precisely

    in three minutes flat

  4. music
    1. lower than a standard pitch
    2. too low in pitch Compare sharp

      she sings flat

  5. fall flat
    to fail to achieve a desired effect, etc
  6. flat out informal.
    1. with the maximum speed or effort
    2. totally exhausted


  1. a flat object, surface, or part
  2. often plural a low-lying tract of land, esp a marsh or swamp
  3. often plural a mud bank exposed at low tide
  4. music
    1. an accidental that lowers the pitch of the following note by one chromatic semitone Usual symbol
    2. a note affected by this accidental Compare sharp
  5. theatre a rectangular wooden frame covered with painted canvas, etc, used to form part of a stage setting
  6. a punctured car tyre
  7. the flat
    (often cap.)
    1. flat racing, esp as opposed to steeplechasing and hurdling
    2. the season of flat racing
  8. nautical a flatboat or lighter
  9. a shallow box or container, used for holding plants, growing seedlings, etc


  1. to make or become flat
  2. music the usual US word for flatten



/ flæt /


  1. a set of rooms comprising a residence entirely on one floor of a building Usual US and Canadian nameapartment
  2. a portion of a house used as separate living quarters
  3. a house shared with people who are not members of one's own family


  1. to live in a flat (with someone)

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Derived Forms

  • ˈflatness, noun
  • ˈflatly, adverb

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Other Words From

  • flat·ly adverb
  • flat·ness noun
  • un·flat·ted adjective

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Word History and Origins

Origin of flat1

First recorded in 1275–1325; Middle English, from Old Norse flatr; akin to Old English flet “the ground, a floor of a house,” Greek platýs “wide, broad”; flat 2; plate

Origin of flat2

First recorded in 1795–1805; variant of obsolete flet, from Old English; flat 1

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Word History and Origins

Origin of flat1

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

Origin of flat2

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

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Idioms and Phrases

  1. fall flat, to fail to produce the desired effect; fail completely:

    His attempts at humor fell flat.

  2. flat aft, Nautical. trimmed so that fore-and-aft sails present as flat a surface as possible, as in sailing close to the wind.
  3. flat out, Informal.
    1. without hesitation; directly or openly:

      He told us flat out he'd been a double agent.

    2. at full speed or with maximum effort.
  4. flat on one's back. back 1( def 48 ).

More idioms and phrases containing flat

  • caught flat-footed
  • fall flat
  • in no time (nothing flat)
  • leave flat

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Synonym Study

See level.

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Example Sentences

Print advertisements for Quaker Rice Cakes from that period show thin, grinning models lying on their flat leotard-covered stomachs to emphasize the lightness of rice cakes.

From Eater

Unlike the flat disk that gave rise to the planets in our own Solar System, the system’s disk consists of three misaligned rings.

It uses technology well, including flat-screen monitors that connect to the Internet and Bluetooth headphones.

From Fortune

The catch included two tiny species with coiled shells about 1 millimeter across, four midsize species with long, conical or urn-shaped shells of about 7 to 11 millimeters, and one species with a flat shell up to 14 millimeters across.

It combines the functionality of a suitcase and the durability of a duffel, with structured sides and interior pockets for ample gear hauling, a flat-bottom design that enables it to stand, and sturdy, oversize wheels.

Luckily enough I have this dedicated flat that is just along from my house that I go to every day.

There were stomachs, taut and flat, but also undulating bellies, soft and bloated from the breakfast buffet.

The program—weirdly—is now under the umbrella of ABC News, and is suffering from flat ratings and an aging demographic.

Another sent back a flat-screen television with a bona fide tombstone within.

Hitchcock settled in southern California, leaving behind a flat in London and a country house in Shamley Green.

Why not have sought out the pure white lime-rocks of the flat country, or the grey granite of the hills?

Then the roof itself, with its gables and dormer windows, softly folded itself flat down upon the top of the house, out of sight.

Instead of writing slander and flat blasphemy, they propose to draw it, and not draw it mild.

There is no other way but fresh blood for it is sheer human nature to feel flat after an effort.

The hills disappear some miles above this city, and henceforward to the sea all is flat and tame as a marsh.


Related Words

Definitions and idiom definitions from Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.




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