sortie n.

late 15c., "fountain, stream," of uncertain origin, probably from French sourge-, stem of sourdre "to rise, swell," from Latin surgere "to rise, arise, get up, mount up, ascend; attack," contraction of surrigere, from assimilated form of sub "up from below" (see sub-) + regere "to keep straight, guide" (from PIE root *reg- "move in a straight line," with derivatives meaning "to direct in a straight line," thus "to lead, rule"). Meaning "high, rolling swell of water" is from 1520s; figurative sense of "excited rising up" (as of feelings) is from 1510s.

late 14c., "that to which one has recourse for aid or assistance, source of comfort and solace," from Old French resort "resource, a help, an aid, a remedy," back-formation from resortir "to resort," literally "to go out again," from re- "again" (see re-) + sortir "go out" (see sortie).

The meaning "place people go for recreation" is recorded by 1754. Phrase in the last resort "ultimately" (1670s) translates French en dernier ressort, originally a last court of legal appeals.