adapter vs handler

adapter

noun
  • One who is capable of adapting to differing situations. 

  • 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. 

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

handler

noun
  • One who handles something (especially manually) or someone. 

  • An advisor or manager to a person occupying a position or office to which the speaker believes the holder does not possess the typical qualifications and/or experience. 

  • A subroutine that handles a particular situation such as an event or exception. 

  • A controller, trainer, someone who handles a specified thing, animal or person (especially a prizefighter). 

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