H

/eɪtʃ/

Definitions of H

1. noun

   the 8th letter of the Roman alphabet
   synonyms: h

   type of:

   alphabetic character, letter, letter of the alphabet

   the conventional characters of the alphabet used to represent speech
2. noun

   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: atomic number 1, hydrogen

   types:

   tritium

   a radioactive isotope of hydrogen; atoms of tritium have three times the mass of ordinary hydrogen atoms

   type of:

   chemical element, element

   any of the more than 100 known substances (of which 92 occur naturally) that cannot be separated into simpler substances and that singly or in combination constitute all matter

   gas

   a fluid in the gaseous state having neither independent shape nor volume and being able to expand indefinitely
3. noun

   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

   a measure of the property of an electric circuit by which an electromotive force is induced in it
4. noun

   (thermodynamics) a thermodynamic quantity equal to the internal energy of a system plus the product of its volume and pressure
   synonyms: enthalpy, heat content, total heat

   type of:

   physical property

   any property used to characterize matter and energy and their interactions