What is the X in X-mas?
late 14c., "that to which one has recourse for aid or assistance," 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). Meaning "place people go for recreation" is first recorded 1754. Phrase in the last resort (1670s) translates French en dernier ressort, originally of legal appeals.
c.1400, "issue; come out again;" mid-15c., "to go to (someone) for aid," from Old French resortir, from resort (see resort (n.)). Related: Resorted; resorting.