| qualifies a boundary which does not allow heat to pass through, or a process which runs in a system without exchange of heat between the system and its surrounding|
NOTE 1 A adiabatic wall has the opposite property as an diathermic wall.
NOTE 2 An approximation of an adiabatic enclosure is e.g. a thermos flask. An approximation of an adiabatic process is a process occurring inside a thermo flask or a process passing so quickly that the exchange of heat with its surrounding is negligible.