[{"Bold_text": "noun", "List Items": ["a person or thing that couples 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."]}]