tryst (n.)

late 14c., "appointment to meet at a certain time and place," from Old French tristre "waiting place, appointed station in hunting," probably from a Scandinavian source such as Old Norse treysta "to trust, make firm," from Proto-Germanic *treuwaz "having or characterized by good faith," from PIE *drew-o-, a suffixed form of the root *deru- "be firm, solid, steadfast." The notion would be "place one waits trustingly." As a verb, late 14c. Related: Trysting.