coupling
cou.pling \'k*p-lin (usual for 2), -*-lin\ n 1: the act of bringing or coming together : PAIRING; specif :: sexual union 2: a device that serves to connect the ends of adjacent parts or objects 3: the joining of or the part of the body that joins the hindquarters to th e forequarters of a quadruped 4: means of electric connection of two electric circuits by having a part c ommon to both