<p><strong>Noun</strong></p><ul><li>the act of a person or thing that couples.</li><li>Machinery: a device for joining two rotating shafts semipermanently at their ends so as to transmit torque from one to the other.</li><li>a part with an inside thread for connecting two pipes of the same diameter.</li><li>a fitting at the end of a length of hose into which the end of another such length can be screwed or fitted.</li><li>Railroads: coupler.</li><li>Electricity: the association of two circuits or systems in such a way that power may be transferred from one to the other; a device or expedient to ensure this.</li><li>a short length of plumbing pipe having each end threaded on the inside.</li><li>the part of the body between the tops of the shoulder blades and the tops of the hip joints in a dog, horse, etc.</li><li>linkage.</li></ul><p><strong>End of Response</strong></p>