couplers

/K AH1 P L ER0 Z/
noun
  1. 1

    Someone who couples things together, especially someone whose job it is to couple railway carriages.

  2. 2

    Anything that serves to couple things together; but especially a device that couples railway carriages.

  3. 3

    A device that connects two keyboards of an organ together so that they play together.

  4. 4

    A device used to convert electronic information into audible sound signals for transmission over telephone lines.

  5. 5

    An electrical device used to transfer energy from one electric device to another, especially without a physical connection.

Source: https://en.wiktionary.org/wiki/coupler, https://en.wiktionary.org/wiki/couplers