intercourse

The word "intercourse" entered English in the late 15th century from the Old French entrecosse (interchange, commerce), which itself was derived from the Latin intercursus, meaning "a running between, an intervention." This Latin term is a noun formed from the past participle of intercurrere, composed of inter- ("between") and currere ("to run"). The original core concept was of a reciprocal "running between" parties, signifying communication, exchange, or connection. Over time, this broad sense of mutual exchange or interaction became semantically specialized. By the late 18th century, it began to be used as a euphemism specifically for sexual connection, a meaning that has since become primary in many contexts, while the general sense of communication or dealings persists in formal or historical usage.

Structure: inter (between, among) + course (a moving or flowing) - inter: A prefix of Latin origin meaning "between, among, mutually, reciprocally." - course: From Latin cursus (a running, a race, a journey), from the verb currere (to run). In this compound, it functions as a noun meaning "a moving, a flow, a progression."