1. [n]  a suite of rooms usually on one floor of an apartment house
2. [n]  scenery consisting of a wooden frame covered with painted canvas; part of a stage setting
3. [n]  a deflated pneumatic tire
4. [n]  a shallow box in which seedlings are started
5. [n]  freight car without permanent sides or roof
6. [n]  a musical notation indicating one half step lower than the note named
7. [n]  a level tract of land
8. [adv]  wholly or completely; "He is flat broke"
9. [adv]  in a forthright manner; candidly or frankly; "he didn't answer directly"; "told me straight out"; "came out flat for less work and more pay"
10. [adj]  stretched out and lying at full length along the ground; "found himself lying flat on the floor"
11. [adv]  at full length; "he fell flat on his face"
12. [adv]  against a flat surface; "he lay flat on his back"
13. [adv]  below the proper pitch; "she sang flat last night"
14. [adv]  with flat sails; "sail flat against the wind"
15. [adj]  lacking variety in shading; "a flat unshaded painting"
16. [adj]  not reflecting light; not glossy; "flat wall paint"; "a photograph with a matte finish"
17. [adj]  (of a tire) completely or partially deflated
18. [adj]  having no depth or thickness
19. [adj]  lacking the expected range or depth; not designed to give an illusion or depth; "a film with two-dimensional characters"; "a flat two-dimensional painting"
20. [adj]  having a horizontal surface in which no part is higher or lower than another; "a flat desk"; "acres of level farmland"; "a plane surface"
21. [adj]  (photography) lacking contrast or shading between tones
22. [adj]  without pleats
23. [adj]  parallel to the ground; "a flat roof"
24. [adj]  not made with leavening; "most flat breads are made from unleavened dough"
25. [adj]  (music) lowered in pitch by one chromatic semitone; "B flat"
26. [adj]  not increasing as the amount taxed increases
27. [adj]  not modified or restricted by reservations; "a categorical denial"; "a flat refusal"
28. [adj]  lacking taste or flavor or tang; "a bland diet"; "insipid hospital food"; "flavorless supermarket tomatoes"; "vapid beer"; "vapid tea"
29. [adj]  having lost effervescence; "flat beer"; "a flat cola"
30. [adj]  lacking stimulating characteristics; uninteresting; "a bland little drama"; "a flat joke"
31. [adj]  (biology) flattened laterally along the whole length (e.g., certain leafstalks or flatfishes)

Flat
Description not available.

more details ...

1. \Flat\, a. [Compar. {Flatter}; superl. {Flattest}.] [Akin
   to Icel. flatr, Sw. flat, Dan. flad, OHG. flaz, and AS. flet
   floor, G. fl["o]tz stratum, layer.]
   1. Having an even and horizontal surface, or nearly so,
      without prominences or depressions; level without
      inclination; plane.
            Though sun and moon Were in the flat sea sunk.
                                                  --Milton.
   2. Lying at full length, or spread out, upon the ground;
      level with the ground or earth; prostrate; as, to lie flat
      on the ground; hence, fallen; laid low; ruined; destroyed.
            What ruins kingdoms, and lays cities flat! --Milton.
            I feel . . . my hopes all flat.       --Milton.
   3. (Fine Arts) Wanting relief; destitute of variety; without
      points of prominence and striking interest.
            A large part of the work is, to me, very flat.
                                                  --Coleridge.
   4. Tasteless; stale; vapid; insipid; dead; as, fruit or drink
      flat to the taste.
   5. Unanimated; dull; uninteresting; without point or spirit;
      monotonous; as, a flat speech or composition.
            How weary, stale, flat, and unprofitable Seem to me
            all the uses of this world.           --Shak.
   6. Lacking liveliness of commercial exchange and dealings;
      depressed; dull; as, the market is flat.
   7. Clear; unmistakable; peremptory; absolute; positive;
      downright.
            Flat burglary as ever was committed.  --Shak.
            A great tobacco taker too, -- that's flat.
                                                  --Marston.
   8. (Mus.)
      (a) Below the true pitch; hence, as applied to intervals,
          minor, or lower by a half step; as, a flat seventh; A
          flat.
      (b) Not sharp or shrill; not acute; as, a flat sound.
   9. (Phonetics) Sonant; vocal; -- applied to any one of the
      sonant or vocal consonants, as distinguished from a
      nonsonant (or sharp) consonant.
   {Flat arch}. (Arch.) See under {Arch}, n., 2. (b).
   {Flat cap}, cap paper, not folded. See under {Paper}.
   {Flat chasing}, in fine art metal working, a mode of
      ornamenting silverware, etc., producing figures by dots
      and lines made with a punching tool. --Knight.
   {Flat chisel}, a sculptor's chisel for smoothing.
   {Flat file}, a file wider than its thickness, and of
      rectangular section. See {File}.
   {Flat nail}, a small, sharp-pointed, wrought nail, with a
      flat, thin head, larger than a tack. --Knight.
   {Flat paper}, paper which has not been folded.
   {Flat rail}, a railroad rail consisting of a simple flat bar
      spiked to a longitudinal sleeper.
   {Flat rods} (Mining), horizontal or inclined connecting rods,
      for transmitting motion to pump rods at a distance.
      --Raymond.
   {Flat rope}, a rope made by plaiting instead of twisting;
      gasket; sennit.
   Note: Some flat hoisting ropes, as for mining shafts, are
         made by sewing together a number of ropes, making a
         wide, flat band. --Knight.
   {Flat space}. (Geom.) See {Euclidian space}.
   {Flat stitch}, the process of wood engraving. [Obs.] -- {Flat
   tint} (Painting), a coat of water color of one uniform shade.
   {To fall flat} (Fig.), to produce no effect; to fail in the
      intended effect; as, his speech fell flat.
            Of all who fell by saber or by shot, Not one fell
            half so flat as Walter Scott.         --Lord
                                                  Erskine.
   

2. \Flat\, adv.
   1. In a flat manner; directly; flatly.
            Sin is flat opposite to the Almighty. --Herbert.
   2. (Stock Exchange) Without allowance for accrued interest.
      [Broker's Cant]
   

3. \Flat\, n.
   1. A level surface, without elevation, relief, or
      prominences; an extended plain; specifically, in the
      United States, a level tract along the along the banks of
      a river; as, the Mohawk Flats.
            Envy is as the sunbeams that beat hotter upon a
            bank, or steep rising ground, than upon a flat.
                                                  --Bacon.
   2. A level tract lying at little depth below the surface of
      water, or alternately covered and left bare by the tide; a
      shoal; a shallow; a strand.
            Half my power, this night Passing these flats, are
            taken by the tide.                    --Shak.
   3. Something broad and flat in form; as:
      (a) A flat-bottomed boat, without keel, and of small
          draught.
      (b) A straw hat, broad-brimmed and low-crowned.
      (c) (Railroad Mach.) A car without a roof, the body of
          which is a platform without sides; a platform car.
      (d) A platform on wheel, upon which emblematic designs,
          etc., are carried in processions.
   4. The flat part, or side, of anything; as, the broad side of
      a blade, as distinguished from its edge.
   5. (Arch.) A floor, loft, or story in a building; especially,
      a floor of a house, which forms a complete residence in
      itself.
   6. (Mining) A horizontal vein or ore deposit auxiliary to a
      main vein; also, any horizontal portion of a vein not
      elsewhere horizontal. --Raymond.
   7. A dull fellow; a simpleton; a numskull. [Colloq.]
            Or if you can not make a speech, Because you are a
            flat.                                 --Holmes.
   8. (Mus.) A character [[flat]] before a note, indicating a
      tone which is a half step or semitone lower.
   9. (Geom.) A homaloid space or extension.
   

4. \Flat\, v. t. [imp. & p. p. {Flatted}; p. pr. & vb. n.
   {Flatting}.]
   1. To make flat; to flatten; to level.
   2. To render dull, insipid, or spiritless; to depress.
            Passions are allayed, appetites are flatted.
                                                  --Barrow.
   3. To depress in tone, as a musical note; especially, to
      lower in pitch by half a tone.
   

5. \Flat\, v. i.
   1. To become flat, or flattened; to sink or fall to an even
      surface. --Sir W. Temple.
   2. (Mus.) To fall form the pitch.
   {To flat out}, to fail from a promising beginning; to make a
      bad ending; to disappoint expectations. [Colloq.]
   

6. \Flat\, a.
   1. (Golf) Having a head at a very obtuse angle to the shaft;
      -- said of a club.
   2. (Gram.) Not having an inflectional ending or sign, as a
      noun used as an adjective, or an adjective as an adverb,
      without the addition of a formative suffix, or an
      infinitive without the sign to. Many flat adverbs, as in
      run fast, buy cheap, are from AS. adverbs in -["e], the
      loss of this ending having made them like the adjectives.
      Some having forms in ly, such as exceeding, wonderful,
      true, are now archaic.
   3. (Hort.) Flattening at the ends; -- said of certain fruits.
   

1. Lacking any complex internal structure. "That bitty box has only a flat file system, not a hierarchical one." The verb form is flatten. Usually used pejoratively (at least with respect to file systems).

2. Said of a memory architecture like that of the VAX or Motorola 680x0 that is one big linear address space (typically with each possible value of a processor register corresponding to a unique address). This is a Good Thing. The opposite is a "segmented" architecture like that of the Intel 80x86 in which addresses are composed from a base-register/offset pair. Segmented designs are generally considered cretinous.

3. A flat domain is one where all elements except bottom are incomparable (equally well defined). E.g. the integers.

[Jargon File]