Adiabatic

a. [ Gr. 'adia`batos not passable; 'a priv. + dia` through + bai`nein to go. ] (Physics) Not giving out or receiving heat. -- Ad`i*a*bat`ic*al*ly, adv. [ Webster 1913 Suppl. ]

☞The adiabatic expansion of carbon dioxide from a compressed container causes the temperature of the gas to decrease rapidly below its freezing point, resulting in the familiar carbon dioxide “snow” emitted by carbon dioxide fire extinguishers. [ PJC. ]

Adiabatic line or
curve, a curve exhibiting the variations of pressure and volume of a fluid when it expands without either receiving or giving out heat. Rankine. [ 1913 Webster ]