a thing that connects two things, especially mechanical components or systems:a hydraulic coupler
Music a device in an organ for connecting two manuals, or a manual with pedals, so that they both sound when only one is played.
(also octave coupler) Music a device in an organ for connecting notes with their octaves above or below.
Photography a compound in a developer or an emulsion which combines with the products of development to form an insoluble dye, part of the image.
(also acoustic coupler) a modem which converts digital signals from a computer into audible sound signals and vice versa, so that the former can be transmitted and received over telephone lines.
