mating vs coupling

mating and coupling both are nouns.

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

As nouns, mating and coupling are synonyms defined as:

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

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

mating (noun)	coupling (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