airlock vs entrance

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. 

entrance

noun
  • The place of entering, as a gate or doorway. 

  • The act of taking possession, as of property, or of office. 

  • The right to go in. 

  • The bow, or entire wedgelike forepart of a vessel, below the water line. 

  • The action of entering, or going in. 

  • The entering upon; the beginning, or that with which the beginning is made; the commencement; initiation. 

  • The beginning of a musician's playing or singing; entry. 

  • The causing to be entered upon a register, as a ship or goods, at a customhouse; an entering. 

  • The angle which the bow of a vessel makes with the water at the water line. 

verb
  • To put into a trance. 

  • To delight and fill with wonder. 

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