airlock vs outlet

airlock

noun
  • 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. 

  • 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. 

outlet

noun
  • A vent or similar passage to allow the escape of something. 

  • A river that runs out of a lake. 

  • Something which allows for the release of one's desires. 

  • A shop that sells the products of a particular manufacturer or supplier. 

  • A wall-mounted device such as a socket or receptacle connected to an electrical system at which current is taken to supply utilization equipment or appliances. 

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