Open English Wordnet
Nouns
(n)coupling, mating, pairing, conjugation, union, sexual unionthe 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”
(n)union, unification, uniting, conjugation, jointurethe act of making or becoming a single unit“the union of opposing factions”, “he looked forward to the unification of his family for the holidays”