blowhole vs inlet

blowhole

noun
  • A top-facing opening to a cavity in the ground very near an ocean's shore, leading to a marine cave from which wave water or bursts of air are expelled. 

  • The spiracle, on the top of the head, through which cetaceans breathe. 

  • A vertical opening in the top of a computer case that lets hot air (primarily from the CPU heat sink) escape quickly. 

  • A vent for the escape of steam or other gas. 

  • An unintended cavity filled with air in a casting product. 

verb
  • To fill or be filled with air in an unintended cavity. 

inlet

noun
  • A body of water let into a coast, such as a bay, cove, fjord or estuary. 

  • A passage that leads into a cavity. 

verb
  • To let in; admit. 

  • To carve the wooden stock of a firearm so as to position the metal components in it. 

  • To insert; inlay. 

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