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. |
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] |
hydrologic |
pertaining to the circulation, distribution, or quality of the waters of the earth, or to the field of hydrology. |
hydrological |
of or pertaining to the study of the earth's waters. |
hydrology |
the scientific study of the distribution, circulation, and quality of the waters of the earth. |
hydrolysis |
the decomposing of a chemical compound by combining it with water or the elements of water. |