medical Definition of law of thermodynamics
1
: conservation of energy — called also
first law of thermodynamics
2
: a law in physics: mechanical work can be derived from the heat in a body only when the body is able to communicate with another at a lower temperature or all actual spontaneous processes result in an increase of total entropy — called also
second law of thermodynamics
3
: a law in physics: at the absolute zero of temperature the entropy of any pure crystalline substance is zero and its derivative with respect to temperature is zero — called also
third law of thermodynamics
