coupling vs mating

coupling and mating both are nouns.

Word	Noun	Adjective	Verb	Adverb
coupling	Yes	No	No	No
mating	Yes	No	No	No

As nouns, coupling and mating are synonyms defined as:

coupling and mating: the act of pairing a male and female for reproductive purposes

Other synonyms of coupling include conjugation, pairing, sexual union, union.

coupling (noun)	mating (noun)
the act of pairing a male and female for reproductive purposes	the act of pairing a male and female for reproductive purposes
a mechanical device that serves to connect the ends of adjacent objects
a connection (like a clamp or vise) between two things so they move together