airlock vs exit

airlock

noun
  • A vestibule, foyer or entranceway with doors to the exterior on one end and doors to the interior on the other, functioning to keep indoor and outdoor air, humidity, and air temperatures separate. 

  • A sealed, airtight chamber, such as in a manned spacecraft or submarine, used to provide access to and from the sealed area without allowing air out or water in. 

exit

noun
  • An opening or passage through which one can go from inside a place (such as a building, a room, or a vehicle) to the outside; an egress. 

  • A minor road (such as a ramp or slip road) which is used to leave a major road (such as an expressway, highway, or motorway). 

  • An act of going out or going away, or leaving; a departure. 

  • The act of departing from life; death. 

  • The action of an actor leaving a scene or the stage. 

verb
  • To depart from life; to die. 

  • To depart from or leave (a place or situation). 

  • To leave a scene or depart from a stage. 

  • Used as a stage direction for an actor: to leave the scene or stage. 

  • To go out or go away from a place or situation; to depart, to leave. 

  • To give up the lead. 

  • To alight or disembark from a vehicle. 

  • To end or terminate (a program, subroutine, etc.) 

How often have the words airlock and exit occurred in a corpus of books? (source: Google Ngram Viewer )