a. [ Gr. 'achrw`matos colorless; 'a priv. + chrw^ma, chrw`matos, color: cf. F. achromatique. ] 1. (Opt.) Free from color; transmitting light without decomposing it into its primary colors. [ 1913 Webster ]

2. (Biol.) Uncolored; not absorbing color from a fluid; -- said of tissue. [ 1913 Webster ]

Achromatic lens (Opt.), a lens composed usually of two separate lenses, a convex and concave, of substances having different refractive and dispersive powers, as crown and flint glass, with the curvatures so adjusted that the chromatic aberration produced by the one is corrected by other, and light emerges from the compound lens undecomposed. --
Achromatic prism. See Prism. --
Achromatic telescope, or
microscope, one in which the chromatic aberration is corrected, usually by means of a compound or achromatic object glass, and which gives images free from extraneous color. [ 1913 Webster ]

adv. In an achromatic manner. [ 1913 Webster ]

n. Achromatism. [ 1913 Webster ]

n. (Biol.) Tissue which is not stained by fluid dyes. W. Flemming. [ 1913 Webster ]

adj. 1. not readily colored by stains; -- of substance of a cell nucleus chromatinic [ WordNet 1.5 ]

v. 1. remove color from.
Syn. -- achromatize, make achromatic [ WordNet 1.5 ]

n. [ Cf. F. achromatisme. ] The state or quality of being achromatic; as, the achromatism of a lens; achromaticity. Nichol. [ 1913 Webster ]

n. [ Cf. F. achromatisation. ] The act or process of achromatizing. [ 1913 Webster ]

v. t. [ imp. & p. p. Achromatized p. pr. & vb. n. Achromatizing ] [ Gr. 'a priv. + &unr_; color. ] To deprive of color; to make achromatic. [ Also spelled achromatise. ] [ 1913 Webster ]

n. [ Gr. 'a priv. + &unr_; color + &unr_; sight. ] Color blindness; inability to distinguish colors; Daltonism. [ 1913 Webster ]

a. [ See Ahromatic. ] Lacking, or deficient in, color; as, achromatous blood. [ Webster 1913 Suppl. ]

a. [ Gr. &unr_; colorless; &unr_; priv. + &unr_; color. ] Free from color; colorless; as, in (Physiol. Chem.), the achromic point of a starch solution acted upon by an amylolytic enzyme is the point at which it fails to give any color with iodine. [ Webster 1913 Suppl. ]

n. [ Gr. &unr_; undistinguishable; 'a priv. + &unr_; to separate, distinguish + &unr_; color. ] Color blindness; achromatopsy. [ 1913 Webster ]

a. [ Pref. apo- + chromatic. ] (Optics) Free from chromatic and spherical aberration; -- said esp. of a lens in which rays of three or more colors are brought to the same focus, the degree of achromatism thus obtained being more complete than where two rays only are thus focused, as in the ordinary achromatic objective. -- Ap`o*chro"ma*tism n. [Webster 1913 Suppl.]

n. [ Pref. bi- + chromate. ] (Chem.) A salt containing two parts of chromic acid to one of the other ingredients; as, potassium bichromate; -- called also dichromate. [ 1913 Webster ]

v. t. To combine or treat with a bichromate, esp. with bichromate of potassium; as, bichromatized gelatine. [ 1913 Webster ]

adj. 1. having two colors.
Syn. -- bicolor, bicolour, bicolored. [ WordNet 1.5 ]

n. [ Gr. &unr_;, &unr_;, bile + &unr_; color. ] (Physiol.) See Bilirubin. [ 1913 Webster ]

n. [ Gr. &unr_; color + -scope. ] An instrument for showing the optical effects of color. [ 1913 Webster ]

n. [ Cf. F. chromate. See Chrome. ] (Chem.) A salt of chromic acid. [ 1913 Webster ]

a. [ L. chromaticus, Gr. &unr_;, suited for color, fr. &unr_;, &unr_;, color; akin to &unr_; color, &unr_; skin, color of the skin. ] 1. Relating to color, or to colors. [ 1913 Webster ]

2. (Mus.) Proceeding by the smaller intervals (half steps or semitones) of the scale, instead of the regular intervals of the diatonic scale. [ 1913 Webster ]

☞ The intermediate tones were formerly written and printed in colors. [ 1913 Webster ]

Chromatic aberration. (Opt.) See Aberration, 4. --
Chromatic printing, printing from type or blocks covered with inks of various colors. --
Chromatic scale (Mus.), the scale consisting of thirteen tones, including the eight scale tones and the five intermediate tones. [ 1913 Webster ]

a. Chromatic. [ Obs. ] [ 1913 Webster ]

adv. In a chromatic manner. [ 1913 Webster ]

n. the quality of a color as determined by its dominant wavelength.
Syn. -- hue. [ WordNet 1.5 ]

n. The science of colors; that part of optics which treats of the properties of colors. [ 1913 Webster ]

n. (Cell Biol.) one of two identical strands into which a chromosome splits during mitosis. [ WordNet 1.5 ]

n. [ Gr. &unr_;, &unr_;, color. ] 1. (Biol.) Tissue which is capable of being stained by dyes. [ archaic ] [ 1913 Webster ]

n. (Biol.) The deeply staining substance of the nucleus and chromosomes of eukaryotic cells, composed of DNA and basic proteins (such as histones), the DNA of which comprises the predominant physical basis of inheritance. It was, at the beginning of the 20th century, supposed to be the same substance as was then termed idioplasm or germ plasm. In most eukaryotic cells, there is also DNA in certain plasmids, such as mitochondria, or (in plant cells) chloroplasts; but with the exception of these cytoplasmic genetic factors, the nuclear DNA of the chromatin is believed to contain all the genetic information required to code for the development of an adult organism. In the interphase nucleus the chromosomes are dispersed, but during cell division or meiosis they are condensed into the individually recognizable chromosomes. The set of chromosomes, or a photographic representation of the full set of chromosomes of a cell (often ordered for presentation) is called a karyotype. [ Webster 1913 Suppl. ]

n. [ Gr. &unr_; a coloring. ] [ 1913 Webster ]

1. (Optics) The state of being colored, as in the case of images formed by a lens. [ 1913 Webster ]

2. (Bot.) An abnormal coloring of plants. [ 1913 Webster ]

a. [ Gr. &unr_;, &unr_;, color + -genous. ] Producing color. [ 1913 Webster ]

n. 1. the paper strip, column, gel, or TLC plate on which subsances have been separated by a process of chromatography{ 2 }. [ PJC ]

2. the record of the results of a process of chromatography{ 2 }, produced by an instrument which measures some property related to the concentration of substances over the course of a chromatographic process. The record may be printed, for example, on a piece of paper, showing the concentration of some substance as a function of time or volume; or it may be retained in a computer and displayed on a video display terminal. The analytical methods for determining which substances have moved to which point on the chromatogram are very varied, and the records of the results of a visualization techique, such as autoradiography, may itself be referred to as a chromatogram. [ PJC ]

n. a piece of equipment used to perform chromatography{ 2 }. [ PJC ]

adj. of or pertaining to chromatography. [ WordNet 1.5 ]

n. [ Gr. &unr_;, &unr_;, color + -graphy. ] 1. A treatise on colors [ archaic ] [ 1913 Webster ]

2. (Chem.) an analytical and preparative technique for separating substances by differences in their selective adsorption to solids, by passing a liquid over the solid, to which the substances to be separated have usually been adsorbed in a preliminary step. The major variations are column chromatography, in which the substances to be separated are adsorbed to a column with any of a wide variety of adsorbing solids in powdered or granulated form; paper chromatography, in which the solids are applied as a spot at one end of a strip of absorbent paper (such as filter paper), and the liquid is percolated through the paper by capillary action; and thin-layer chromatography (TLC), which is similar to paper chromatography, but the adsorbent material is, instead of paper, a thin layer of finely powdered material, such as cellulose or silica, on a backing of glass or plastic, called a TLC plate. A modern version of column chromatography is high-performance liquid chromatography, usually referred to as HPLC. [ PJC ]

n. [ Gr. &unr_;, &unr_;, color + -logy. ] A treatise on colors. [ 1913 Webster ]

n. [ Gr. &unr_;, &unr_;, color + fe`rein to bear. ] 1. (Zool.) A contractile cell or vesicle containing liquid pigment and capable of changing its form or size, thus causing changes of color in the translucent skin of such animals as possess them. They are highly developed and numerous in the cephalopods. [ 1913 Webster ]

2. (Bot.) One of the granules of protoplasm, which in mass give color to the part of the plant containing them. [ 1913 Webster ]

n. [ Gr. &unr_;, &unr_;, color + -scope. ] (Astron.) A reflecting telescope, part of which is made to rotate eccentrically, so as to produce a ringlike image of a star, instead of a point; -- used in studying the scintillation of the stars. [ 1913 Webster ]

n. A chromosphere. [ R. ] [ 1913 Webster ]

n. [ Gr. &unr_; color + &unr_; turn, rotation, &unr_; to turn. ] 1. (Physics) An instrument for exhibiting certain chromatic effects of light (depending upon the persistence of vision and mixture of colors) by means of rapidly rotating disks variously colored. [ 1913 Webster ]

2. A device in a magic lantern or stereopticon to produce kaleidoscopic effects. [ 1913 Webster ]

n. [ Gr. &unr_; color + &unr_; type. ] [ 1913 Webster ]

1. (Photog.) A colored photographic picture taken upon paper made sensitive with potassium bichromate or some other salt of chromium. [ 1913 Webster ]

2. The process by which such picture is made. [ 1913 Webster ]

n. Same as Chromium. [ 1913 Webster ]

Chrome alum (Chem.), a dark violet substance, (SO4)3Cr2.K2SO4.24H2O, analogous to, and crystallizing like, common alum. It is regarded as a double sulphate of chromium and potassium. --
Chrome green (a) The green oxide of chromium, Cr2O3, used in enamel painting, and glass staining. (b) A pigment made by mixing chrome yellow with Prussian blue. --
Chrome red, a beautiful red pigment originally prepared from the basic chromate of lead, but now made from red oxide of lead. --
Chrome yellow, a brilliant yellow pigment, PbCrO4, used by painters. [ 1913 Webster ]

v. t. [ imp. & p. p. Chromed p. pr. & vb. n. Chroming. ] [ From Chrome, n. ] To treat with a solution of potassium bichromate, as in dyeing. [ Webster 1913 Suppl. ]

. Same as Chromium steel, under Steel. [ Webster 1913 Suppl. ]

n. a form of synesthesia in which nonvisual stimulation results in the experience of color sensations. [ Also spelled chromaesthesia. ] [ WordNet 1.5 ]

a. (Chem.) Pertaining to, or obtained from, chromium; -- said of the compounds of chromium in which it has its higher valence. [ 1913 Webster ]

Chromic acid, an acid, H2CrO4, analogous to sulphuric acid, not readily obtained in the free state, but forming well known salts, many of which are colored pigments, as chrome yellow, chrome red, etc. --
Chromic anhydride, a brilliant red crystalline substance, CrO3, regarded as the anhydride of chromic acid. It is one of the most powerful oxidizers known. [ 1913 Webster ]

n. [ Gr. &unr_; a kind of fish. ] (Zool.) One of the Chromidæ, a family of fresh-water fishes abundant in the tropical parts of America and Africa. Some are valuable food fishes, as the bulti of the Nile. [ 1913 Webster ]

‖n. [ NL., fr. Gr. &unr_; color + &unr_; sweat. ] (Med.) Secretion of abnormally colored perspiration. [ 1913 Webster ]

n. Same as Chromatism. [ 1913 Webster ]

n. 1. (Min.) A black submetallic mineral consisting of oxide of chromium and iron; -- called also chromic iron. [ 1913 Webster ]

2. (Chem.) A compound or salt of chromous hydroxide regarded as an acid. [ R. ] [ 1913 Webster ]

n. [ NL., fr. Gr. &unr_; color. ] (Chem.) A comparatively rare element occurring most abundantly in the mineral chromite. Atomic weight 52.5. Symbol Cr. When isolated it is a hard, brittle, grayish white metal, fusible with difficulty. Its chief commercial importance is for its compounds, as potassium chromate, lead chromate, etc., which are brilliantly colored and are used dyeing and calico printing. Called also chrome. [ 1913 Webster ]