from
The Collaborative International Dictionary of English v.0.48
Coupling \Coup"ling\ (-l?ng), n.
1. The act of bringing or coming together; connection; sexual
union.
[1913 Webster]
2. (Mach.) A device or contrivance which serves to couple or
connect adjacent parts or objects; as, a belt coupling,
which connects the ends of a belt; a car coupling, which
connects the cars in a train; a shaft coupling, which
connects the ends of shafts.
[1913 Webster]
{Box coupling}, {Chain coupling}. See under {Box}, Chain.
{Coupling box}, a coupling shaped like a journal box, for
clamping together the ends of two shafts, so that they may
revolve together.
{Coupling pin}, a pin or bolt used in coupling or joining
together railroad cars, etc.
[1913 Webster]