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"
Act of joining together to form a couple.
"The wedding ceremony focused on the joyful coupling of the bride and groom in marriage."
In plain English: Coupling is when two things are joined together so they work as a single unit.
"The train moves forward by connecting each carriage with a strong metal coupling between them."
Usage: Use this term specifically when referring to two people becoming partners, rather than the mechanical device that connects parts or the general state of being in love. It is often confused with "coupling" as an action verb, but here it functions strictly as a noun describing the event itself.
present participle of couple
"The coupling between the two train cars was secured as they began to move forward."
In plain English: Coupling means connecting two things together so they work as a single unit.
"The train engineer will connect the two cars by coupling them together before departure."
The word coupling comes from Middle English and originally referred to the act of joining two things together as a pair. It entered modern usage by combining the verb "couple" with the suffix "-ing" to describe this connecting action.