Plain English Meaning

Frozen carbon dioxide. It is much colder than regular ice and turns straight into gas instead of melting into water. Mechanics sometimes use it to shrink a metal part so it slips into place, then warms up and locks in tight.

Full Definition

Solid carbon dioxide (CO2) at approximately -109.3°F (-78.5°C) that sublimates directly from solid to gas at atmospheric pressure without passing through a liquid phase. In aviation maintenance, it is used as an extreme cold source for shrink-fitting metal parts and for chilling components during certain repair and assembly procedures.