n. 1. self induced fluorescence. [ WordNet 1.5 ]

n. [ Boron + fluoride. ] (Chem.) A double fluoride of boron and hydrogen, or some other positive element, or radical; -- called also fluoboride, and formerly fluoborate. [ 1913 Webster ]

‖n. [ L., a flowing, fr. fluere to flow. See Fluent. ] 1. A fluid state. [ Obs. ] Sir I. Newton. [ 1913 Webster ]

2. Menstrual flux; catamenia; menses. [ Obs. ] [ 1913 Webster ]

3. (Min.) See Fluorite. [ 1913 Webster ]

‖ [ L., white flow. ] (Med.) The whites; leucorrhæa. [ 1913 Webster ]

n. [ Fluorene + anthracene. ] (Chem.) A white crystalline hydrocarbon C15H10, of a complex structure, found as one ingredient of the higher boiling portion of coal tar. [ 1913 Webster ]

a. (Chem.) Combined with fluorine; subjected to the action of fluoride. [ R. ] [ 1913 Webster ]

n. (Chem.) A colorless, crystalline hydrocarbon, C13H10 having a beautiful violet fluorescence; whence its name. It occurs in the higher boiling products of coal tar, and is obtained artificially. [ 1913 Webster ]

n. (Chem.) A yellowish red, crystalline substance, C20H12O5, produced by heating together phthalic anhydride and resorcin; -- so called, from the very brilliant yellowish green fluorescence of its alkaline solutions. It has acid properties, and its salts of the alkalies are known to the trade under the name of uranin.
Syn. -- fluorescein, fluorescent dye, resorcinolphthalein. [ 1913 Webster ]

n. [ From Fluor. ] (Chemistry, Optics) A luminescence emitted by certain substances due to the absorption of radiation at one wavelength, and the almost instantaneous re-emission of radiation at another, usually longer wavelength. The re-radiation stops almost as soon as the incident radiation is halted, thus distinguishing this phenomenon from phosphorescence, in which re-radiation of light may continue for some time after the incident radiation is halted. The color of the radiated light typically differs from the apparent color of the material, as when green crystals of fluor spar afford blue reflections. It is due not to the difference in the color of a distinct surface layer, but to the power which the substance has of modifying the light incident upon it, by first absorbing the light to achieve an excited state, and then radiating light to resume the ground energy level. The light emitted by fluorescent substances is in general of longer wavelength than the incident light. The radiation can also be induced by ionizing radiation which is not electromagnetic, such as alpha or beta rays, and cathode rays. This property is possessed by fluorspar, uranium glass, sulphide of calcium, and many other substances. It finds use in analytical instruments to detect or measure radiation, and in some commercial applications. [ 1913 Webster +PJC ]

a. Having the property of fluorescence. [ 1913 Webster ]

n. (Chem.) A colorless, amorphous substance which is produced by the reduction of fluoresceïn, and from which the latter may be formed by oxidation. [ 1913 Webster ]

a. [ Cf. F. fluorique. ] (Chem.) Pertaining to, obtained from, or containing, fluorine. [ 1913 Webster ]

v. t. To subject to fluoridation, as of water; to add fluoride to.
Syn. -- fluoridize. [ WordNet 1.5 ]

n. The addition of a fluoride to the water supply (to prevent dental decay).
Syn. -- fluoridization. [ WordNet 1.5 ]

n. [ Cf. F. fluoride. ] (Chem.) A binary compound of fluorine with another element or radical. [ 1913 Webster ]

Calcium fluoride (Min.), fluorite, CaF2. See Fluorite. [ 1913 Webster ]

n. the addition of a fluoride to the water supply (to prevent dental decay).
Syn. -- fluoridation. [ WordNet 1.5 ]

v. t. to subject to fluoridation, as of water.
Syn. -- fluoridate. [ WordNet 1.5 ]

n. [ NL. fluorina: cf. G. fluorin, F. fluorine. So called from its occurrence in the mineral fluorite. ] (Chem.) A non-metallic, gaseous element of atomic number 9, strongly acid or negative, and associated with chlorine, bromine, and iodine, in the halogen group of which it is the first member. It always occurs combined, is very active chemically, and possesses such an avidity for most elements, and silicon especially, that it can neither be prepared nor kept in glass vessels, but may be contained in lead vessels. If set free it immediately attacks a containing glass vessel, so that it was not isolated until 1886. It is a pungent, corrosive, colorless gas. Symbol F. Atomic weight 19.00. [ 1913 Webster ]

☞ Fluorine unites with hydrogen to form hydrofluoric acid, which is the agent employed in etching glass. It occurs naturally, principally combined as calcium fluoride in fluorite, and as a double fluoride of aluminium and sodium in cryolite. [ 1913 Webster ]

n. (Min.) Calcium fluoride (CaF2), a mineral of many different colors, white, yellow, purple, green, red, etc., often very beautiful, crystallizing commonly in cubes with perfect octahedral cleavage; also massive. It is used as a flux. Some varieties are used for ornamental vessels. Also called fluor spar, or simply fluor. [ 1913 Webster ]

n. Any of various fluorescent substances used in fluorescence microscopy to stain specimens. [ WordNet 1.5 ]

n. [ Fluor + -oid. ] (Crystallog.) A tetrahexahedron; -- so called because it is a common form of fluorite. [ 1913 Webster ]

n. [ Fluorescence + -scope. ] 1. (Phys.) An instrument for observing or exhibiting fluorescence. [ 1913 Webster ]

2. (Physics) A fluorescent screen, with hood to protect the eyes, used for observing the shadows cast by objects placed in the path of the X rays. -- Flu*or`o*scop"ic a. [Webster 1913 Suppl.]

n. Examination of an object, as the human body, by exposing it to the X rays and observing the shadow cast upon a fluorescent screen; cryptoscopy. [ Webster 1913 Suppl. ]

a. Pertaining to fluor. [ 1913 Webster ]

(Min.) See Fluorite. [ 1913 Webster ]

a. [ Hydro-, 2 + fluoric. ] (Chem.) Pertaining to, or containing, hydrogen and fluorine; fluohydric; as, hydrofluoric acid. [ 1913 Webster ]

Hydrofluoric acid (Chem.), a colorless, mobile, volatile liquid, HF, very corrosive in its action, and having a strong, pungent, suffocating odor. It is produced by the action of sulphuric acid on fluorite, and is usually collected as a solution in water. It attacks all silicates, as glass or porcelain, is the agent employed in etching glass, and is preserved only in vessels of platinum, lead, caoutchouc, or gutta-percha. [ 1913 Webster ]

a. (Chem.) Containing, or composed of, silicon and fluorine; especially, denoting the compounds called silicofluorides. [ 1913 Webster ]

Silicofluoric acid (Chem.), a compound of hydrofluoric acid and silicon fluoride, known only in watery solution. It is produced by the action of silicon fluoride on water, and is regarded as an acid, H2SiF6, and the type and origin of the silicofluorides. [ 1913 Webster ]

n. (Chem.) A fluosilicate; a salt of silicofluoric acid. [ 1913 Webster ]

n. (Chem.) Any one of a series of double fluorides of tin (stannum) and some other element. [ 1913 Webster ]

n. (Chem.) A double fluoride of zirconium and hydrogen, or some other positive element or radical; as, zircofluoride of sodium. [ 1913 Webster ]