- A chamber or passage that separates the inside of a spacecraft, submarine, or other sealed vessel from the outside environment.
- A mechanical device used in diving that prevents the loss of air from the lungs when changing pressure.
- A device used to prevent the loss of air from a building or room to the outside environment.
From air + lock, from the sense of a barrier or restriction in airflow.
- The astronaut entered the airlock and prepared for the spacewalk.
- The airlock is used to equalize the pressure between the inside and the outside of the sub.
- The airlock system is used to prevent the loss of air conditioning in the building.
- The diver used the airlock to safely surface from the deep dive.
- The airlock is the last barrier before entering the vacuum of space.