What is the X in X-mas?
c.1200, "to be very hot; to afflict painfully with hot liquid or steam," from Old North French escalder "to scald, to scorch" (Old French eschalder "heat, boil up, bubble," Modern French échauder), from Late Latin excaldare "bathe in hot water" (source also of Spanish escaldar, Italian scaldare "heat with hot water"), from Latin ex- "off" (see ex-) + calidus "hot" (see calorie). Related: Scalded; scalding. The noun is c.1600, from the verb.
v. scald·ed, scald·ing, scalds
To burn with a hot liquid or steam. n.
A body injury caused by scalding.