From Latin 'intercursus' (running between) — originally any exchange; narrowed to sexual contact only in the 20th century.
Communication or dealings between individuals, groups, or countries; sexual intercourse; exchange or interaction of any kind.
From Old French 'entrecours,' from Latin 'intercursus' (a running between, intervention), from 'intercurrere' (to run between, to intervene), composed of 'inter-' (between) and 'currere' (to run). The original meaning was any kind of exchange or communication between parties — a running between them, a back-and-forth flow. 'Intercourse' meant commerce, diplomatic exchange, intellectual interaction, and social contact for centuries
There is a town in Pennsylvania called Intercourse, founded in 1754. The name originally referred to a crossroads — a place where roads ran between each other, a point of intersection and exchange. The town's name preserves the eighteenth-century meaning of 'intercourse' perfectly: a meeting point, a place of traffic and trade. The sexual connotation that makes the name seem humorous today did not dominate