gangboard vs mule

gangboard

noun
  • A board or plank placed within or without the bulwarks of a vessel's waist for lookouts to walk or stand on. 

  • The boards ending the hammock-nettings at either side of the entrance from the accommodation-ladder to the deck. 

  • A board or plank used as a temporary footbridge between a ship and a dockside or any gap such as scaffolding. 

mule

noun
  • A kind of triangular sail for a yacht. 

  • The generally sterile male or female hybrid offspring of a male donkey and a female horse. 

  • A coin or medal minted with obverse and reverse designs not normally seen on the same piece, either intentionally or in error. 

  • Any of a group of cocktails involving ginger ale or ginger beer, citrus juice, and various liquors. 

  • The generally sterile hybrid offspring of any two species of animals. 

  • A stubborn person. 

  • A kind of cotton-spinning machine. 

  • A shoe that has no fitting or strap around the heel, but which covers the foot. 

  • A MMORPG character, or NPC companion in a tabletop RPG, used mainly to store extra inventory for the owner's primary character. 

  • A person paid to smuggle drugs. 

verb
  • To smuggle (illegal drugs). 

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