0 the process of becoming lower in air pressure or causing a closed space, especially the inside of an aircraft, to become lower in air pressure:
Short-term depressurization of a commercial jet at high altitudes would cause unconsciousness but not death.
A hole formed on the top of the plane's fuselage near the tail, resulting in depressurization of the cabin.
If it had been a cabin depressurization the passengers' oxygen masks would have dropped down.
