dongle vs relocatable power tap

dongle

noun
  • Any small device that plugs into an electronic device, typically a computer, and alters its functionality. Common examples include wireless modems, digital media players, software copy protect devices, and adapters. 

  • A hardware device utilized by a specific application for purposes of copy protection. 

relocatable power tap

noun
  • A multi-socket power cord that can be used to channel electricity from a single socket. 

How often have the words dongle and relocatable power tap occurred in a corpus of books? (source: Google Ngram Viewer )