n.

1. 連結者；配合者
2. 聯結器

n.

1. something that connects or couples two things.
2. 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.
3. (also acoustic coupler) a modem which converts digital signals into audible signals and vice versa so that they can be transmitted and received over telephone lines.