blowhole vs rail

blowhole

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

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. 

rail

verb
  • To sexually penetrate in a rough manner. 

  • To enclose with rails or a railing. 

  • To range in a line. 

  • To place on a track. 

  • To travel by railway. 

  • To complain violently (against, about). 

noun
  • A horizontal bar extending between supports and used for support or as a barrier; a railing. 

  • A large line (portion or serving of a powdery illegal drug). 

  • A railroad; a railway, as a means of transportation. 

  • A conductor maintained at a fixed electrical potential relative to ground, to which other circuit components are connected. 

  • Any of several birds in the family Rallidae. 

  • One of the lengthwise edges of a surfboard. 

  • A horizontal piece of wood that serves to separate sections of a door or window. 

  • The metal bar forming part of the track for a railroad. 

  • A vertical section on one side of a web page. 

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