plural of hydrogen maser atomic clock

Hydrogen that is generated entirely with power from renewable energy and the electrolysis of water; which generates no carbon pollution.

hydrogen generated from methane feedstock, typically from natural gas/petroleum gas, whose carbon residue, typically carbon dioxide, is captured, resulting in a low-carbon process.

(historical) The prevention and control of venereal disease, prostitution, drug abuse, and vice, employing scientific research and advertising techniques.

Synonym of hybrid learning

An extinct subspecies of spotted hyena, Crocuta crocuta spelaea, which lived in Eurasia during the Pleistocene.

Alternative spelling of oxyhydrogen

(epidemiology) The combination of natural immunity and artificially acquired immunity, such as that induced by a vaccine.

The solid phase of hydrogen; frozen hydrogen state / Synonym of metal hydride / A metal lattice which has absorbed hydrogen gas / Used other than figuratively or idiomatically: see solid, hydrogen.

plural of hybrid electric vehicle