rawl plug vs spigot

rawl plug

noun
  • A wall plug; a screw anchor. 

spigot

noun
  • The plug of a faucet, tap or cock. 

  • A water tap: a faucet or sillcock. 

  • A pin or peg used to stop the vent in a cask. 

verb
  • To block with a spigot. 

  • To insert (a spigot). 

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