a person or thing that couples or links together.

Machinery . a rod or link transmitting force and motion between a rotating part and a rotating or oscillating part.

Also called coupling. Railroads . a device for joining pieces of rolling stock.

a device in an organ or harpsichord for connecting keys, manuals, or a manual and pedals, so that they are played together when one is played.

Electricity . a device for transferring electrical energy from one circuit to another, as a transformer that joins parts of a radio apparatus together by induction.

(in color photography) a chemical that reacts with the developer to produce one of the colors in a print or transparency.

noun

device , drawbar , fastener , link , ring , shackle