Late Middle English: from Old French entrecours 'exchange, commerce', from Latin intercursus, from intercurrere 'intervene', from inter- 'between' + currere 'run'. The specifically sexual use arose in the late 18th century.

• cursor from Middle English:

  Nowadays we call the movable indicator on our computer screen the cursor. In medieval English a cursor was a running messenger: it is a borrowing of the Latin word for ‘a runner’, and comes from currere ‘to run’. From the late 16th century cursor became the term for a sliding part of a slide rule or other instrument, marked with a line for pinpointing the position on a scale that you want, the forerunner of the computing sense. Currere is the source of very many English words including course (Middle English) something you run along; concourse (Late Middle English) originally a crowd who had ‘run together’; current (Middle English) originally meaning ‘running, flowing’; discursive (late 16th century) running away from the point; excursion (late 16th century) running out to see things; intercourse (Late Middle English) originally an exchange running between people; and precursor (Late Middle English) one who goes before; as well as supplying the cur part of concur (Late Middle English); incur (Late Middle English); occur (Late Middle English) (from ob- ‘against’); and recur (Middle English).