c.1300, from O.Fr. batisier (11c.), from L. baptizare, from Gk. baptizein "to immerse, to dip in water," also used figuratively, e.g. "to be over one's head" (in debt, etc.), "to be soaked (in wine);" in Gk. Christian usage, "baptize;" from baptein "to dip, steep, dye, color," from PIE base *gwabh- "to dip, sink." Christian baptism originally consisted in full immersion. Related: Baptismal (adj., 1640s).
British spelling of baptize (q.v.); for suffix, see -ize.