| hydraulics |
(used with a sing. verb) the science or technology concerned with the mechanical uses of fluids, esp. water, in motion. |
| hydrazine |
a colorless and corrosive fuming liquid substance of nitrogen and hydrogen that is used in rocket and jet fuels. |
| hydric |
of, relating to, or preferring a moist or wet environment. [2 definitions] |
| hydride |
an inorganic compound, such as sodium hydride, containing hydrogen and a second usu. electropositive element or group. |
| hydro- |
water. [2 definitions] |
| hydrocarbon |
any of various organic compounds that contain only hydrogen and carbon, such as methane or ethylene. |
| hydrocephalus |
a condition, esp. in children, in which an abnormal amount of serum accumulates in the brain's ventricles, causing the skull to enlarge and the brain to compress. |
| hydrochloric acid |
a strong poisonous acid of hydrogen and chlorine in a water solution, esp. used for industrial and chemical purposes. |
| hydrochloride |
a salt formed by the combination of hydrochloric acid and an organic base. |
| hydrocortisone |
the hormone cortisol used pharmaceutically. |
| 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. |