enthalpy

UK: /ˈɛnθəlpɪ/ US: (en′thal pē, en thal′-)

Inflections of 'enthalpy' (n): npl: enthalpies

WordReference Random House Unabridged Dictionary of American English © 2026

en•thal•py  (en′thal pē, en thal′-), n., pl. -pies. [Thermodynamics.]

1. Thermodynamics a quantity associated with a thermodynamic system, expressed as the internal energy of a system plus the product of the pressure and volume of the system, having the property that during an isobaric process, the change in the quantity is equal to the heat transferred during the process. Symbol: H  Also called heat content, total heat. 

• Greek enthálp(ein) to warm in (en- en-² + thálpein to warm) + -y³
• 1925–30

Collins Concise English Dictionary © HarperCollins Publishers::

enthalpy / ˈɛnθəlpɪ ɛnˈθæl-/ noun

1. a thermodynamic property of a system equal to the sum of its internal energy and the product of its pressure and volume
   Symbol: H
   Also called: heat content, total heat

Etymology: 20th Century: from Greek enthalpein to warm in, from en-² + thalpein to warm