- adjective referring to a change in temperature in a mass of air, which occurs when the air is compressed or expanded by an increase or decrease in atmospheric pressure and does not involve the air losing heat to, or gaining heat from, its surroundings
- A condition in which there is no heat gain or heat loss.
- A process or event in which there is no change in the heat content of a system. The system does not exchange heat with its surroundings.
- A change occurring without a gain or loss of heat.