Open English Wordnet
Nouns
(n)hydrogen, H, atomic number 1a nonmetallic univalent element that is normally a colorless and odorless highly flammable diatomic gas; the simplest and lightest and most abundant element in the universe
(n)heat content, total heat, enthalpy, H(thermodynamics) a thermodynamic quantity equal to the internal energy of a system plus the product of its volume and pressure“enthalpy is the amount of energy in a system capable of doing mechanical work”