Christening

google

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Old English crīstnian ‘make Christian’, from crīsten ‘Christian’, from Latin Christianus, from Christus ‘Christ’.

wiktionary

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From Middle English cristenyng, from Old English cristnung; compare christen +‎ -ing.

etymonline

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christening (n.)

"act or ceremony of baptizing," c. 1300, verbal noun from christen (v.). Old English had cristnung.