H meaning

H as a 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

   Synonyms: hydrogen, atomic number 1

   Type of: chemical element, gas

   Kinds: tritium

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

   Synonyms: henry

   Type of: inductance unit

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

   Synonyms: Planck's constant

   Type of: factor of proportionality

4. the 8th letter of the Roman alphabet

   Type of: letter

5. (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

   Synonyms: heat content, total heat, enthalpy

   Type of: physical property

How to pronounce H

H is pronounced /eɪtʃ/ in American English. It has 1 syllable.