coupling

nouns

a connection (like a clamp or vise) between two things so they move together
coupling, yoke
is derived from
couple
a mechanical device that serves to connect the ends of adjacent objects
coupler, coupling
is derived from
couple
the act of pairing a male and female for reproductive purposes
"the casual couplings of adolescents"; "the mating of some species occurs only in the spring"
conjugation, coupling, mating, pairing, sexual union, union
is derived from
couple