n. [ Cf. F. compressibilité. ] The quality of being compressible of being compressible; as, the compressibility of elastic fluids. [ 1913 Webster ]

a. [ Cf. F. compressible. ] Capable of being pressed together or forced into a narrower compass, as an elastic or spongy substance. [ 1913 Webster ]

n. The quality of being compressible; compressibility. [ 1913 Webster ]

n. [ L. compressio: cf. F. compression. ] 1. The act of compressing, or state of being compressed. “Compression of thought.” Johnson. [ 1913 Webster ]

2. (Computers) reduction of the space required for storage (of binary data) by an algorithm which converts the data to a smaller number of bits while preserving the information content. The act of compressing { 3 }. Compression may be lossless compression, in which all of the information in the original data is preserved, and the original data may be recovered in form identical to its original form; or lossy compression, in which some of the information in the original data is lost, and decompression results in a data form slightly different from the original. Lossy compression is used, for example, to compress audio or video recordings, and sometimes images, where the slight differences in the original data and the data recovered after lossy compression may be imperceptable to the human eye or ear. The JPEG format is produced by a lossy compression algorithm. [ PJC ]

. A projectile constructed so as to take the grooves of a rifle by means of a soft copper band firmly attached near its base or, formerly, by means of an envelope of soft metal. In small arms the modern projectile, having a soft core and harder jacket, is subjected to compression throughout the entire cylindrical part. [ Webster 1913 Suppl. ]

a. [ Cf. F. compressif. ] Compressing, or having power or tendency to compress; as, a compressive force. [ 1913 Webster ]

n. 1. the process of experiencing decompression; the act or process of relieving or reducing pressure.
Syn. -- decompression. [ WordNet 1.5 +PJC ]

n. 1. the process of experiencing decompression; the act or process of relieving or reducing pressure.
Syn. -- decompressing. [ WordNet 1.5 +PJC ]

2. the reduction of atmospheric pressure experienced by divers rising from deep water to the surface, thus reducing the concentration of dissolved atmospheric gases in the blood; -- especially applied to a gradual reduction of such pressure. [ PJC ]

3. the process, analogous to sense 2, undergone by divers in a decompression chamber, in which an artificially high atmospheric pressure is gradually lowered to normal pressure. [ PJC ]

4. a return to a normal, more relaxed state after a period of intense stress, psychological pressure, or urgent activity; -- of people. [ PJC ]

5. (Computers) the process of converting digitally encoded data from a more compact (compressed) form to its original, larger size. The process of compression and decompression may completely recover all of the original data (called lossless compression), or may lose some of the original data in order to achieve higher degress of compression (lossy compression). The latter is used especially with images or video data, which may be of very large size relative to text, and for which small changes may be imperceptible to the human eye. The JPEG data compression format is a lossy format. [ PJC ]

adv. In a depressing manner. [ 1913 Webster ]

n. [ L. depressio: cf. F. dépression. ] 1. The act of depressing. [ 1913 Webster ]

2. The state of being depressed; a sinking. [ 1913 Webster ]

3. A falling in of the surface; a sinking below its true place; a cavity or hollow; as, roughness consists in little protuberances and depressions. [ 1913 Webster ]

4. Humiliation; abasement, as of pride. [ 1913 Webster ]

5. Dejection; despondency; lowness. [ 1913 Webster ]

In a great depression of spirit. Baker. [ 1913 Webster ]

6. Diminution, as of trade, etc.; inactivity; dullness. [ 1913 Webster ]

7. (Astron.) The angular distance of a celestial object below the horizon. [ 1913 Webster ]

8. (Math.) The operation of reducing to a lower degree; -- said of equations. [ 1913 Webster ]

9. (Surg.) A method of operating for cataract; couching. See Couch, v. t., 8. [ 1913 Webster ]

Angle of depression (Geod.), one which a descending line makes with a horizontal plane. --
Depression of the dewpoint (Meteor.), the number of degrees that the dew-point is lower than the actual temperature of the atmosphere. --
Depression of the pole, its apparent sinking, as the spectator goes toward the equator. --
Depression of the visible horizon. (Astron.) Same as Dip of the horizon, under Dip.

Syn. -- Abasement; reduction; sinking; fall; humiliation; dejection; melancholy. [ 1913 Webster ]

a. Able or tending to depress or cast down. -- De*press"ive*ness, n. [1913 Webster]

‖a. [ It. ] (Mus.) With expression. [ 1913 Webster ]

a. Capable of being expressed, squeezed out, shown, represented, or uttered. -- Express"i*bly,adv. [1913 Webster]

n. [ L. expressio: cf. F. expression. ] 1. The act of expressing; the act of forcing out by pressure; as, the expression of juices or oils; also, of extorting or eliciting; as, a forcible expression of truth. [ 1913 Webster ]

2. The act of declaring or signifying; declaration; utterance; as, an expression of the public will. [ 1913 Webster ]

With this tone of philosophy were mingled expressions of sympathy. Prescott. [ 1913 Webster ]

3. Lively or vivid representation of meaning, sentiment, or feeling, etc.; significant and impressive indication, whether by language, appearance, or gesture; that manner or style which gives life and suggestive force to ideas and sentiments; as, he reads with expression; her performance on the piano has expression. [ 1913 Webster ]

The imitators of Shakespeare, fixing their attention on his wonderful power of expression, have directed their imitation to this. M. Arnold. [ 1913 Webster ]

4. That which is expressed by a countenance, a posture, a work of art, etc.; look, as indicative of thought or feeling. “The expression of an eye.” Tennyson. [ 1913 Webster ]

It still wore the majesty of expression so conspicuous in his portraits by the inimitable pencil of Titian. Prescott. [ 1913 Webster ]

5. A form of words in which an idea or sentiment is conveyed; a mode of speech; a phrase; as, a common expression; an odd expression. [ 1913 Webster ]

6. (Math.) The representation of any quantity or relation by appropriate characters or symbols, usually in a specific order. [ 1913 Webster +PJC ]

7. (Genetics) the production of products by a gene that cause the appearance of the corresponding protein or phenotype; -- of a gene or of an organism with a specific gene; as, the expression the beta-galactosidase positive phenotype, [ PJC ]

8. (Computers) a combination of characters linked by operators, occurring as part of the code of a computer program, which must be evaluated according to the rules of the computer language in order to produce a resulting value. [ PJC ]

In most programming languages, (a + b) is an expression indicating simple arithmetic addition, if the variables a and b are real numbers. Many other types of operation may be used in programs, and each set of symbols indicating an operation is an expression in that program. [ PJC ]

Past expression,
Beyond expression, beyond the power of description. “Beyond expression bright.” Milton. [ 1913 Webster ]

a. Of, or relating to, expression; phraseological; also, vividly representing or suggesting an idea or sentiment. Fitzed. Hall. Ruskin. [ 1913 Webster ]

n. 1. an art movement early in the 20th century; the artist's subjective expression of inner experiences was emphasized. [ WordNet 1.5 ]

2. a genre of German painting that tried to show the subjective responses to scenes rather than the scenes themselves. [ WordNet 1.5 ]

n. an artist who is an adherent of expressionism. [ WordNet 1.5 ]

adj. 1. of or pertaining to expressionism (definition 2); as, expressionist art. [ WordNet 1.5 ]

a. Destitute of expression. [ 1913 Webster ]

a. [ Cf. F. expressif. ] 1. Serving to express, utter, or represent; indicative; communicative; -- followed by of; as, words expressive of his gratitude. [ 1913 Webster ]

Each verse so swells expressive of her woes. Tickell. [ 1913 Webster ]

2. Full of expression; vividly representing the meaning or feeling meant to be conveyed; significant; emphatic; as, expressive looks or words. [ 1913 Webster ]

You have restrained yourself within the list of too cold an adieu; be more expressive to them. Shak. [ 1913 Webster ]

Through her expressive eyes her soul distinctly spoke. Littelton.

-- Ex*press"ive*ly,adv. -- Ex*press"ive*ness, n. [ 1913 Webster ]

n. the quality of being expressive. [ WordNet 1.5 ]

n. The quality of being impressible; susceptibility. [ 1913 Webster ]

a. [ Cf. F. impressible. ] Capable of being impressed; susceptible; sensitive. -- Im*press"i*ble*ness, n. -- Im*press"i*bly, adv. [ 1913 Webster ]

n. [ F. impression, L. impressio. ] 1. The act of impressing, or the state of being impressed; the communication of a stamp, mold, style, or character, by external force or by influence. [ 1913 Webster ]

2. That which is impressed; stamp; mark; indentation; sensible result of an influence exerted from without. [ 1913 Webster ]

The stamp and clear impression of good sense. Cowper. [ 1913 Webster ]

To shelter us from impressions of weather, we must spin, we must weave, we must build. Barrow. [ 1913 Webster ]

3. That which impresses, or exercises an effect, action, or agency; appearance; phenomenon. [ Obs. ] [ 1913 Webster ]

Portentous blaze of comets and impressions in the air. Milton. [ 1913 Webster ]

A fiery impression falling from out of Heaven. Holland. [ 1913 Webster ]

4. Influence or effect on the senses or the intellect hence, interest, concern. Reid. [ 1913 Webster ]

His words impression left. Milton. [ 1913 Webster ]

Such terrible impression made the dream. Shak. [ 1913 Webster ]

I have a father's dear impression,
And wish, before I fall into my grave,
That I might see her married. Ford. [ 1913 Webster ]

5. An indistinct notion, remembrance, or belief. [ 1913 Webster ]

6. Impressiveness; emphasis of delivery. [ 1913 Webster ]

Which must be read with an impression. Milton. [ 1913 Webster ]

7. (Print.) The pressure of the type on the paper, or the result of such pressure, as regards its appearance; as, a heavy impression; a clear, or a poor, impression; also, a single copy as the result of printing, or the whole edition printed at a given time; as, a copy from the fifth impression. [ 1913 Webster ]

Ten impressions which his books have had. Dryden. [ 1913 Webster ]

8. In painting, the first coat of color, as the priming in house painting and the like. [ R. ] [ 1913 Webster ]

9. (Engraving) A print on paper from a wood block, metal plate, or the like. [ 1913 Webster ]

Proof impression, one of the early impressions taken from an engraving, before the plate or block is worn. [ 1913 Webster ]

n. The quality of being impressionable. [ 1913 Webster ]

a. [ Cf. F. impressionnable. ] Liable or subject to impression; capable of being molded; susceptible; impressible; as, a bad influence on impressionable youths. [ 1913 Webster ]

He was too impressionable; he had too much of the temperament of genius. Motley. [ 1913 Webster ]

A pretty face and an impressionable disposition. T. Hook. [ 1913 Webster ]

n. The quality of being impressionable. [ 1913 Webster ]

n. [ F. impressionnisme. ] (Fine Arts) The theory or method of suggesting an effect or impression without elaboration of the details; -- a disignation of a recent fashion in painting and etching. [ 1913 Webster ]

n. [ F. impressionniste. ] (Fine Arts) One who adheres to the theory or method of impressionism in art; especially, a painter who paints in the impressionistic style; as, the skyrocketing prices of paintings by the French impressionists. [ 1913 Webster ]

a. Pertaining to, or characterized by, impressionism. [ 1913 Webster ]

a. Having the quality of not being impressed or affected; not susceptible. [ 1913 Webster ]

a. [ Cf. F. impressif. ] 1. Making, or tending to make, an impression; having power to impress; adapted to excite attention and feeling, to touch the sensibilities, or affect the conscience; as, an impressive discourse; an impressive scene. [ 1913 Webster ]

2. Capable of being impressed. [ Obs. ] Drayton.

-- Im*press"ive*ly, adv. -- Im*press"ive*ness, n. [ 1913 Webster ]

n. [ Cf. F. incompressibilité. ] The quality of being incompressible, or incapable of reduction in volume by pressure; -- formerly supposed to be a property of liquids. [ 1913 Webster ]

The incompressibility of water is not absolute. Rees. [ 1913 Webster ]

a. [ Pref. in- not + compressible: cf. F. incompressible. ] Not compressible; incapable of being reduced by force or pressure into a smaller compass or volume; resisting compression; as, many liquids and solids appear to be almost incompressible. -- In`com*press"i*ble*ness, n. [1913 Webster]

a. Not capable of expression or utterance in language; ineffable; unspeakable; indescribable; unutterable; as, inexpressible grief or pleasure. “Inexpressible grandeur.” Blair. [ 1913 Webster ]

In orbs
Of circuit inexpressible they stood. Milton. [ 1913 Webster ]

n. pl. Breeches; trousers; ; underwear generally, especially women's; -- now usually referred to as unmentionables. [ Colloq. or Slang ] Ld. Lytton. [ 1913 Webster +PJC ]

adv. In an inexpressible manner or degree; unspeakably; unutterably. Spectator. [ 1913 Webster ]

a. 1. Inexpressible. [ R. ] [ 1913 Webster ]

2. Without expression or meaning; not expressive; dull; unintelligent; as, an inexpressive countenance. [ 1913 Webster ]

n. The state or quality of being inexpressive. [ 1913 Webster ]

a. Not oppressive or burdensome. O. Wolcott. [ 1913 Webster ]

a. That can not be suppressed or concealed; irrepressible. Young. -- In`sup*press"i*bly, adv. [1913 Webster]

a. Insuppressible. [ Obs. ] “The insuppressive mettle of our spirits.” Shak. [ 1913 Webster ]

n. Pressure acting within. [ R. ] [ 1913 Webster ]

a. Not capable of being repressed, restrained, or controlled; as, irrepressible joy; an irrepressible conflict. W. H. Steward. [ 1913 Webster ]

adv. In a manner or to a degree that can not be repressed. [ 1913 Webster ]

n. (Computers) The compression of binary data into a form which, when it is re-expanded, has most, but not all, of the original information. It is used primarily for compression of images and sounds, and is designed to provide a high degree of compression at the cost of a slight loss of data. It is expemplified by the JPEG compression standard. Images compressed by a lossy compression algorithm are re-expanded into an image close, but not identical to the original image; the difference between the original and the reconstructed image may be imperceptible to normal viewing by the eye. [ PJC ]

n. (Med.), A person suffering from manic-depressive psychosis. [ PJC ]

n. (Med.), A mental disorder characterized by alternating episodes of mania and depression.
Syn. -- bipolar disorder, manic depression, manic depressive illness. [ WordNet 1.5 ]

n. Wrong expression. [ 1913 Webster ]

n. [ F., fr. L. oppressio. ] 1. The act of oppressing, or state of being oppressed. [ 1913 Webster ]

2. That which oppresses; a hardship or injustice; cruelty; severity; tyranny. “The multitude of oppressions.” Job xxxv. 9. [ 1913 Webster ]

3. A sense of heaviness or obstruction in the body or mind; depression; dullness; lassitude; as, an oppression of spirits; an oppression of the lungs. [ 1913 Webster ]

There gentle Sleep
First found me, and with soft oppression seized
My drowsed sense. Milton. [ 1913 Webster ]

4. Ravishment; rape. [ Obs. ] Chaucer. [ 1913 Webster ]