*horu*

v. i. [ imp. & p. p. Chorused p. pr. & vb. n. Chorusing. ] To sing in chorus; to exclaim simultaneously. W. D. Howells. [ 1913 Webster ]

n. [ Nl., fr. L. corchorus a poor kind of pulse, Gr. ko`rchoros a wild plant of bitter taste. ] (Bot.) The common name of the Kerria Japonica or Japan globeflower, a yellow-flowered, perennial, rosaceous plant, seen in old-fashioned gardens. [ 1913 Webster ]

n. [ NL., fr. Gr. kry`os icy cold, frost + fe`rein to bear. ] (Chem.) An instrument used to illustrate the freezing of water by its own evaporation. The ordinary form consists of two glass bulbs, connected by a tube of the same material, and containing only a quantity of water and its vapor, devoid of air. The water is in one of the bulbs, and freezes when the other is cooled below 32° Fahr. [ 1913 Webster ]

n. a genus of tropical Old World ferns having closely crowded circular sori and no indusia.
Syn. -- genus Cyclophorus. [ WordNet 1.5 ]

‖n.; pl. ‖Electrophori [ NL., fr. combining form electro- + Gr. fe`rein to bear. ] (Physics) An instrument for exciting electricity, and repeating the charge indefinitely by induction, consisting of a flat cake of resin, shellac, or ebonite, upon which is placed a plate of metal. [ 1913 Webster ]

n.; pl. Phosphori [ L., the morning star, Gr. fwsfo`ros, lit., light bringer; fw^s light + fe`rein to bring. ] 1. The morning star; Phosphor. [ 1913 Webster ]

2. (Chem.) A poisonous nonmetallic element of the nitrogen group, obtained as a white, or yellowish, translucent waxy substance, having a characteristic disagreeable smell; this waxy allotropic form is also called yellow phosphorus, to distinguish it from another allotropic form, red phosphorus. It is very active chemically, must be preserved under water, and unites with oxygen even at ordinary temperatures, giving a faint glow, -- whence its name. It always occurs combined, usually in phosphates, as in the mineral apatite, in bones, etc. It is used in the composition on the tips of friction matches, and for many other purposes. It is an essential component of the genetic material of all living organisms. The molecule contains four atoms. Symbol P. Atomic weight 31.0. [ 1913 Webster ]

3. (Chem.) Hence, any substance which shines in the dark like phosphorus, as certain phosphorescent bodies. [ 1913 Webster ]

Bologna phosphorus (Chem.), sulphide of barium, which shines in the dark after exposure to light; -- so called because this property was discovered by a resident of Bologna. The term is sometimes applied to other compounds having similar properties. --
Metallic phosphorus (Chem.), an allotropic modification of phosphorus, obtained as a gray metallic crystalline substance, having very inert chemical properties. It is obtained by heating ordinary phosphorus in a closed vessel at a high temperature. --
Phosphorus disease (Med.), a disease common among workers in phosphorus, giving rise to necrosis of the jawbone, and other symptoms. --
Red phosphorus, or
Amorphous phosphorus (Chem.), an allotropic modification of phosphorus, obtained as a dark red powder by heating ordinary phosphorus in closed vessels. It is not poisonous, is not phosphorescent, and is only moderately active chemically. It is valuable as a chemical reagent, and is used in the composition of the friction surface on which safety matches are ignited. --
Solar phosphori (Chem.), phosphorescent substances which shine in the dark after exposure to the sunlight or other intense light. --
yellow phosphorus (Chem.), the waxy yellow allotropic form of elemental phosphorus. See also phosphorus{ 2 }. [ 1913 Webster +PJC ]

. A steel in which the amount of phosphorus exceeds that of carbon. [ Webster 1913 Suppl. ]

‖n. [ NL. See Pyrophorous. ] (Old Chem.) Any one of several substances or mixtures which phosphoresce or ignite spontaneously on exposure to air, as a heated mixture of alum, potash, and charcoal, or a mixture of charcoal and finely divided lead. [ 1913 Webster ]