adapter vs extension cord

adapter

noun
  • Specifically, a device that permits two, three, or more plugs to be used at a single electrical power point. 

  • One who adapts a thing, e.g. a play. 

  • Specifically, a device that allows one format of plug to be used with a different format of socket. 

  • Specifically, an AC adapter: a device that reduces voltage and converts AC to DC to allow a battery-powered device to use mains power. 

  • A device or application used to achieve operative compatibility between devices that otherwise are incompatible. 

  • One who is capable of adapting to differing situations. 

extension cord

noun
  • An electrical cord with a plug one end, and a single socket or a multi-port socket at the other end, used for powering one or more devices at a distance, too far from the wall outlet to be reached by the normal cords of the device or devices. 

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