Origins
The English word 'intercourse' entered the language around 1425, from Old French 'entrecours,' which descended from Latin 'intercursus' (a running between, an intervening). The Latin verb 'intercurrere' combines 'inter-' (between) and 'currere' (to run), producing the image of running between — moving back and forth between two parties, carrying something (goods, messages, ideas) from one to the other.
For nearly five centuries, 'intercourse' was a respectable, even elegant word for any kind of exchange between people, groups, or nations. Commercial intercourse meant trade. Diplomatic intercourse meant relations between states. Social intercourse meant friendly dealings. Intellectual intercourse meant the exchange of ideas. The word carried connotations of civilized, productive interaction — the running between that makes society, commerce, and culture possible.
The phrase 'sexual intercourse' appeared in the eighteenth century, alongside many other uses of the word. It was initially just one of many 'intercourses' — physical intimacy described through the same metaphor of exchange and running-between that described trade and diplomacy. But over the course of the nineteenth and twentieth centuries, the sexual sense gradually eclipsed all others. By the mid-twentieth century, 'intercourse' used alone was overwhelmingly interpreted as referring to sexual contact.
Modern Usage
This semantic narrowing is a textbook example of how a euphemism can consume its host word. 'Sexual intercourse' began as a polite, clinical way to refer to an act that English speakers were reluctant to name directly. But the euphemism became so strongly associated with its referent that the broader meanings of 'intercourse' were crowded out. Today, using 'intercourse' to mean 'diplomatic dealings' or 'intellectual exchange' sounds quaint or inadvertently humorous — the word has been captured by its most specific sense.
The broader meanings survive in historical texts and in fixed phrases. 'Social intercourse,' 'commercial intercourse,' and 'intercourse between nations' appear in eighteenth- and nineteenth-century writing without any sexual connotation. The U.S. Constitution uses 'intercourse' in the sense of trade and dealings. Legal and diplomatic texts from before the twentieth century use the word freely in its original range of meanings.
The town of Intercourse, Pennsylvania (founded 1754), preserves the pre-sexual meaning perfectly. The name referred to a crossroads — a place where roads ran between each other, a point of intersection, exchange, and traffic. Other American towns with the same name (Intercourse, Alabama, for instance) have similar origins. These place names are now sources of amusement because the word's semantic center of gravity has shifted so decisively.
Latin Roots
The Latin root connects 'intercourse' to the broader 'currere' family. 'Course' is a path of running. 'Discourse' (dis- + currere) is running in various directions — conversation. 'Recourse' (re- + currere) is running back — turning to something for help. 'Concourse' (con- + currere) is running together — a gathering. 'Intercourse' (inter- + currere) is running between — exchange. Each prefix defines a different spatial relationship, and each spatial relationship generates a different social meaning.
The word's history is a reminder that language changes, and that words which were perfectly neutral in one century can become loaded in another. 'Intercourse' in its Latin, French, and early English forms was simply a word for the flow of communication and exchange between people. Its current primary association with sexuality is an accident of cultural history — a meaning that swelled until it swallowed the rest. The Latin image of running between remains the true etymological core: exchange, reciprocity, the back-and-forth that makes connection possible.