enthalpy

 
Pronunciation: /ˈɛnθ(ə)lpi, ɛnˈθalpi/

noun

Physics
  • a thermodynamic quantity equivalent to the total heat content of a system. It is equal to the internal energy of the system plus the product of pressure and volume. (Symbol: H)
  • the change in enthalpy associated with a particular chemical process: most compounds have negative enthalpies of formation

Origin:

1920s: from Greek enthalpein 'warm in', from en- 'within' + thalpein 'to heat'