'Flat file' definitions:

Definition of 'flat file'

From: WordNet

noun

A file with two flat surfaces

Definition of 'Flat file'

From: GCIDE

Flat \Flat\ (fl[a^]t), a. [Compar. Flatter (fl[a^]t"r[~e]r); superl. Flattest (fl[a^]t"t[e^]st).] [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. [1913 Webster]
Though sun and moon Were in the flat sea sunk. --Milton. [1913 Webster]
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. [1913 Webster]
What ruins kingdoms, and lays cities flat! --Milton. [1913 Webster]
I feel . . . my hopes all flat. --Milton. [1913 Webster]
3. (Fine Arts) Wanting relief; destitute of variety; without points of prominence and striking interest. [1913 Webster]
A large part of the work is, to me, very flat. --Coleridge. [1913 Webster]
4. Tasteless; stale; vapid; insipid; dead; as, fruit or drink flat to the taste. [1913 Webster]
5. Unanimated; dull; uninteresting; without point or spirit; monotonous; as, a flat speech or composition. [1913 Webster]
How weary, stale, flat, and unprofitable Seem to me all the uses of this world. --Shak. [1913 Webster]
6. Lacking liveliness of commercial exchange and dealings; depressed; dull; as, the market is flat. [1913 Webster]
7. Clear; unmistakable; peremptory; absolute; positive; downright.
Syn: flat-out. [1913 Webster]
Flat burglary as ever was committed. --Shak. [1913 Webster]
A great tobacco taker too, -- that's flat. --Marston. [1913 Webster]
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. [1913 Webster]
9. (Phonetics) Sonant; vocal; -- applied to any one of the sonant or vocal consonants, as distinguished from a nonsonant (or sharp) consonant. [1913 Webster]
10. (Golf) Having a head at a very obtuse angle to the shaft; -- said of a club. [Webster 1913 Suppl.]
11. (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. [Webster 1913 Suppl.]
12. (Hort.) Flattening at the ends; -- said of certain fruits. [Webster 1913 Suppl.]
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. [1913 Webster]
Of all who fell by saber or by shot, Not one fell half so flat as Walter Scott. --Lord Erskine. [1913 Webster]