Machinery. a rod or link transmitting force and motion between a rotating part and a rotating or oscillating part.
3.
Also called coupling.Railroads. a device for joining pieces of rolling stock.
4.
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.
5.
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.