Browse Dictionary by Letter

Comprehensive
Dictionary Suite
Help
Help
Help
A   B   C   D   E   F   G   H   I   J   K   L   M   N   O   P   Q   R   S   T   U   V   W   X   Y   Z
hydrocyanic acid a highly poisonous, flammable solution of hydrogen cyanide in water, used in manufacturing, working with metals, and the like; prussic acid.
hydrodynamics (used with a sing. verb) the science concerned with the motion of fluids, esp. as it relates to solid objects immersed in fluid, or with the motion of solid objects through fluids.
hydroelectric of or concerning the generation of electricity by means of the energy produced by moving water.
hydrofluoric acid a highly poisonous water solution of hydrogen fluoride, colorless and corrosive, used esp. in etching glass.
hydrofoil a winglike structure that is attached to a vessel to raise its hull above the water when the vessel is moving and thus to increase its speed. [2 definitions]
hydrogen a chemical element that contains one proton in each nucleus and that occurs naturally in many compounds such as water, acids, petroleum hydrocarbons, and carbohydrates, and in pure form as a highly flammable, lighter-than-air gas used in many industrial applications, such as the hydrogenation of fats and oils. (symbol: H) (Cf. deuterium, protium, tritium.)
hydrogenate to treat or cause to combine with hydrogen.
hydrogen bomb an extremely powerful bomb whose destructive energy comes from the fusion of hydrogen nuclei under intense heat and pressure, forming helium nuclei.
hydrogen ion the positive ion of a hydrogen atom whose electron has been removed, as in acids.
hydrogen peroxide an unstable compound of hydrogen and oxygen whose water solution is used mostly as an antiseptic or bleach.
hydrogen sulfide a poisonous, colorless gas that has the odor of rotten eggs and is used mostly in chemical manufacturing and metallurgy.
hydrography the study or science of describing or mapping the earth's bodies of water, esp. in relation to navigational or commercial uses.
hydroid characteristic of the asexual hydrozoan polyp. [2 definitions]
hydrolysis the decomposing of a chemical compound by combining it with water or the elements of water.
hydrolyte a substance that has gone through the process of hydrolysis.
hydrolyze to subject to or undergo hydrolysis.
hydrometer an instrument, usu. a sealed glass tube containing a graduated scale and weighted at one end, used to measure the specific gravity of liquids.
hydropathy the treatment of disease by the use of water, as by drinking or external application. (Cf. hydrotherapy.)
hydrophobia a deadly viral disease of the central nervous system, usu. transmitted by the bite of an infected animal; rabies. [2 definitions]
hydrophyte a plant that grows in water alone or in esp. wet ground.
hydroplane a light, fast motorboat that at high speeds skims the water with only the rear part of the hull touching the surface. [5 definitions]