'christening' ultimately originates from Old English and Middle English forms of the verb 'christen', and can be traced back through Late Latin 'christinare', where the element 'christ-' comes from Greek 'christos' meaning 'anointed'.

'christening' developed from Middle English (e.g. 'christening', 'christenen') which in turn came from Old English 'cristnian' and Late Latin 'christinare', itself related to Latin 'Christianus' (from Greek 'christos').

Initially it meant 'to make Christian; to baptize', and over time extended to mean 'to give a name (at baptism)' and, by extension, 'to formally name or inaugurate' in secular contexts.