'rechristen' originates from the prefix 're-' (from Latin 're-', meaning 'again') combined with 'christen', ultimately from Old English 'cristnian' referring to 'make Christian' (related to 'Christ').

'christen' came from Old English 'cristnian' and Middle English 'christenen'; the productive prefix 're-' (Latin) was attached in Modern English to form 'rechristen' meaning 'to christen again' and later extended figuratively to mean 'rename'.

Initially, it meant 'to make Christian or to baptize'; over time it retained that literal sense but also extended to the broader modern meaning 'to give a new name' (often used figuratively).