Coup"ling (-l?ng), n.
1.
The act of bringing or coming together; connection; sexual union.
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.
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.
© Webster 1913.