H

noun

1. a 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

   noun.substance

   Synonyms atomic number 1 hydrogen

   Source: WordNet 3.0

2. a unit of inductance in which an induced electromotive force of one volt is produced when the current is varied at the rate of one ampere per second

   noun.quantity

   Synonyms henry

   Source: WordNet 3.0

3. the constant of proportionality relating the energy of a photon to its frequency; approximately 6.626 x 10^-34 joule-second

   noun.quantity

   Source: WordNet 3.0

4. the 8th letter of the Roman alphabet

   noun.communication

   Source: WordNet 3.0

5. (thermodynamics) a thermodynamic quantity equal to the internal energy of a system plus the product of its volume and pressure

   noun.attribute

   Examples

   Enthalpy is the amount of energy in a system capable of doing mechanical work.

   Synonyms enthalpy heat content total heat

   Source: WordNet 3.0