*hydro*

a. [ Gr. &unr_; wanting water; 'an priv. + "y`dwr water.] Destitute of water; as, anhydrous salts or acids. [1913 Webster]

a. (Med.) Counteracting or preventing hydrophobia. -- n. A remedy for hydrophobia. [ 1913 Webster ]

a. (Med.) Good against dropsy. -- n. A remedy for dropsy. [ 1913 Webster ]

n. [ Pref. bi- + hydroguret. ] (Chem.) A compound of two atoms of hydrogen with some other substance. [ Obs. ] [ 1913 Webster ]

v. t. (Chem.) To deprive of, or free from, hydrogen. [ 1913 Webster ]

n. (Chem.) The act or process of freeing from hydrogen; also, the condition resulting from the removal of hydrogen. [ 1913 Webster ]

n. (Chem.) Same as Deutohydroguret.

n. [ Pref. deut-, deuto- + hydroguret. ] (Chem.) A compound containing in the molecule two atoms of hydrogen united with some other element or radical. [ Obs. ] [ 1913 Webster ]

‖n. [ NL. See Enhydrous. ] (Min.) A variety of chalcedony containing water. [ 1913 Webster ]

a. [ Gr. &unr_;; &unr_; in + &unr_; water. ] Having water within; containing fluid drops; -- said of certain crystals. [ 1913 Webster ]

{ . } 1. A combining form from Gr. &unr_;, &unr_;, water (see Hydra). [ 1913 Webster ]

2. (Chem.) A combining form of hydrogen, indicating hydrogen as an ingredient, as hydrochloric; or a reduction product obtained by hydrogen, as hydroquinone. [ 1913 Webster ]

n. 1. A hydro-aëroplane. [ obsolescent ] [ Webster 1913 Suppl. ]

2. hydroelectric power; -- also used attributively. [ PJC ]

. (Aëronautics) An aëroplane with a boatlike or other understructure that enables it to travel on, or to rise from the surface of, a body of water by its own motive power; -- now usually referred to as a seaplane. [ obsolescent ] [ Webster 1913 Suppl. +PJC ]

n. [ Hydro-, 1 + barometer. ] An instrument for determining the depth of the sea water by its pressure. [ 1913 Webster ]

n. [ Hydro-, 2 + bilirubin. ] (Physiol. Chem.) A body formed from bilirubin, identical with urobilin. [ 1913 Webster ]

n. A hydro-aëroplane having two supporting planes. [ Webster 1913 Suppl. ]

‖n. pl. [ NL., fr. Gr. "y`dwr water + &unr_; gills.] (Zool.) An extensive artificial division of gastropod mollusks, including those that breathe by gills, as contrasted with the Pulmonifera. -- Hy`dro*bran"chi*ate a. [ 1913 Webster ]

n. (Chem.) Same as Hydrobromide. [ 1913 Webster ]

a. [ Hydro-, 2 + bromic. ] (Chem.) Composed of hydrogen and bromine; as, hydrobromic acid. [ 1913 Webster ]

Hydrobromic acid (Chem.), a colorless, pungent, corrosive gas, HBr, usually collected as a solution in water. It resembles hydrochloric acid, but is weaker and less stable. Called also hydrogen bromide. [ 1913 Webster ]

n. (Chem.) A compound of hydrobromic acid with a base; -- distinguished from a bromide, in which only the bromine unites with the base. [ 1913 Webster ]

n. [ Hydro-, 2 + carbon. ] (Chem.) A compound containing only hydrogen and carbon, as methane, benzene, etc.; also, by extension, any of their derivatives. [ 1913 Webster ]

Hydrocarbon burner,
furnace,
stove, a burner, furnace, or stove with which liquid fuel, as petroleum, is used. [ 1913 Webster ]

a. Of the nature, or containing, hydrocarbons. [ 1913 Webster ]

n. (a) (Old Chem.) A hydrocarbon. [ Obs. ] (b) (Chem.) A hydrous carbonate, as malachite. [ 1913 Webster ]

n. [ Hydro-, 2 + carbostyril. ] (Chem.) A white, crystalline, nitrogenous hydrocarbon, C9H9NO, obtained from certain derivatives of cinnamic acid and closely related to quinoline and carbostyril. [ 1913 Webster ]

n. [ Hydro-, 2 + carburet. ] (Chem.) Carbureted hydrogen; also, a hydrocarbon. [ Obs. ] [ 1913 Webster ]

n.; pl. Hydrocauli [ NL., fr. Gr. "y`dwr water + &unr_; a stalk.] (Zool.) The hollow stem of a hydroid, either simple or branched. See Illust. of Gymnoblastea and Hydroidea. [1913 Webster]

n. [ L., fr. Gr. &unr_;; "y`dwr water + &unr_; tumor.] (Med.) A collection of serous fluid in the areolar texture of the scrotum or in the coverings, especially in the serous sac, investing the testicle or the spermatic cord; dropsy of the testicle. [1913 Webster]

a. Relating to, or connected with, hydrocephalus, or dropsy of the brain. [ 1913 Webster ]

a. [ Hydrocephalus + -oid. ] (Med.) Resembling hydrocephalus. [ 1913 Webster ]

Hydrocephaloid affection (Med.), the group of symptoms which follow exhausting diarrhea in young children, resembling those of acute hydrocephalus, or tubercular meningitis. [ 1913 Webster ]

a. Having hydrocephalus. “Hydrocephalous offspring.” G. Eliot. [ 1913 Webster ]

n. [ NL., fr. Gr. &unr_; hydrocephalus; "y`dwr water + &unr_; head.] (Med.) An accumulation of liquid within the cavity of the cranium, especially within the ventricles of the brain; dropsy of the brain. It is due usually to tubercular meningitis. When it occurs in infancy, it often enlarges the head enormously. [1913 Webster]

n. (Chem.) Same as Hydrochloride. [ 1913 Webster ]

a. [ Hydro-, 2 + chloric: cf. F. hydrochlorique. ] (Chem.) Pertaining to, or compounded of, chlorine and hydrogen gas; as, hydrochloric acid; chlorhydric. [ 1913 Webster ]

Hydrochloric acid (Chem.), hydrogen chloride; a colorless, corrosive gas, HCl, of pungent, suffocating odor. It is made in great quantities in the soda process, by the action of sulphuric acid on common salt. It has a great affinity for water, and the commercial article is a strong solution of the gas in water. It is a typical acid, and is an indispensable agent in commercial and general chemical work. Called also muriatic acid and chlorhydric acid. [ 1913 Webster ]

n. (Chem.) A compound of hydrochloric acid with a base; -- distinguished from a chloride, where only chlorine unites with the base. [ 1913 Webster ]

‖n. pl. [ NL. See Hydra, and Coral. ] (Zool.) A division of Hydroidea, including those genera that secrete a stony coral, as Millepora and Stylaster. Two forms of zooids in life project from small pores in the coral and resemble those of other hydroids. See Millepora. [ 1913 Webster ]

n. (Chem.) See Hydrocyanide. [ 1913 Webster ]

a. [ Hydro-, 2 + anic: cf. F. hydrocyanique. ] (Chem.) Pertaining to, or derived from the combination of, hydrogen and cyanogen. [ 1913 Webster ]

Hydrocyanic acid (Chem.), a colorless, mobile, volatile liquid, HCN, having a characteristic peach-blossom odor. It is one of the most deadly poisons. It is made by the action of sulphuric acid on yellow prussiate of potassium (potassium ferrocyanide), and chemically resembles hydrochloric and hydrobromic acids. Called also prussic acid, hydrogen cyanide, etc. [ 1913 Webster ]

n. (Chem.) A compound of hydrocyanic acid with a base; -- distinguished from a cyanide, in which only the cyanogen so combines.

{ } a. [ Hydro-, 1 + dynamic, -ical: cf. F. hydrodynamique. ] Pertaining to, or derived from, the dynamical action of water of a liquid; of or pertaining to water power. [ 1913 Webster ]

Hydrodynamic friction, friction produced by the viscosity of a liquid in motion. [ 1913 Webster ]

n. [ Hydro-, 1 + dynamics: cf. F. hydrodynamique. ] That branch of the science of mechanics which relates to fluids, or, as usually limited, which treats of the laws of motion and action of nonelastic fluids, whether as investigated mathematically, or by observation and experiment; the principles of dynamics, as applied to water and other fluids. [ 1913 Webster ]

☞ The word is sometimes used as a general term, including both hydrostatics and hydraulics, together with pneumatics and acoustics. See Hydraulics. [ 1913 Webster ]

n. [ Hydro-, 1 + dynamometer. ] An instrument to measure the velocity of a liquid current by the force of its impact. [ 1913 Webster ]

a. [ Hydro-, 1 + electric. ] Pertaining to, employed in, or produced by, the evolution of electricity by means of a battery in which water or steam is used. [ 1913 Webster ]

Hydro-electric machine (Physics), an apparatus invented by Sir William Armstrong of England for generating electricity by the escape of high-pressure steam from a series of jets connected with a strong boiler, in which the steam is produced. [ 1913 Webster ]

n. [ Hydro-, 1 + extractor. ] An apparatus for drying anything, as yarn, cloth, sugar, etc., by centrifugal force; a centrifugal. [ 1913 Webster ]

n. [ Hydro-, 2 + ferricyanic. ] (Chem.) Pertaining to, or containing, or obtained from, hydrogen, ferric iron, and cyanogen; as, hydroferricyanic acid. See Ferricyanic. [ 1913 Webster ]

a. [ Hydro-, 2 + ferrocyanic. ] (Chem.) Pertaining to, or containing, or obtained from, hydrogen, ferrous iron, and cyanogen; as, hydroferrocyanic acid. See Ferrocyanic. [ 1913 Webster ]

n. (Chem.) A supposed compound of hydrofluoris acid and a base; a fluoride. [ Archaic ] [ 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 ]

n. (Chem.) A salt of hydrofluosilic acid; a silicofluoride. See Silicofluoride. [ 1913 Webster ]