(inorganic chemistry) The hydrated form of alumina, having the formula Al(OH)₃; it reacts with bases to form aluminates.

A hypothetical future economy in which the primary form of stored energy for mobile applications and load balancing is hydrogen (H₂), and, in particular, hydrogen replaces fossil fuels in automobiles.

(medicine) A usually congenital condition in which an abnormal accumulation of fluid in the cerebral ventricles causes enlargement of the skull and compression of the brain, destroying much of the neural tissue

Pertaining to hygiene; clean, sanitary. / (computing, slang, of a macro) Whose expansion is guaranteed not to cause the accidental capture of identifiers.

A gas hydrate that contains methane as the guest molecule; It occurs both in deep sedimentary structures, and as outcrops on the ocean floor.

(nautical) a high-speed ship that supports its weight by means of wings (hydrofoils) beneath the surface of the water

(chemistry) Used other than figuratively or idiomatically: see hydrogen, ion. ; H⁻ or H⁺

(chemistry) a crystalline compound having an isometric ice lattice containing cages that incorporate small guest gas molecules; they are stable at moderate pressure and low temperature

A dam containing hydroelectric generators.

A low-speed electric generator driven by water turbines.