Baptism
Middle English: from Old French baptesme, via ecclesiastical Latin from ecclesiastical Greek baptismos ‘ceremonial washing’, from baptizein ‘immerse, baptize’.
wiktionary
From Middle English bapteme, baptesme, from Old French batesme or bapteme, from Ecclesiastical Latin, Late Latin baptisma, from Ancient Greek βάπτισμα(báptisma, “dipping, baptism”), from βαπτίζω(baptízō, “I dip in liquid”).
etymonline
baptism (n.)
"initiatory sacrament of the Christian faith, consisting in immersion in or application of water by an authorized administrator," c. 1300, bapteme, from Old French batesme, bapteme "baptism" (11c., Modern French baptême), from Latin baptismus, from Greek baptismos, noun of action from baptizein (see baptize). The -s- was restored in late 14c.
The signification, qualifications, and methods of administration have been much debated. Figurative sense "any ceremonial ablution as a sign of purification, dedication, etc." is from late 14c. Old English used fulluht in this sense (John the Baptist was Iohannes se Fulluhtere).
Phrase baptism of fire "a soldier's first experience of battle" (1857) translates French baptême de feu; the phrase originally was ecclesiastical Greek baptisma pyros and meant "the grace of the Holy Spirit as imparted through baptism;" later it was used of martyrdom, especially by burning.
