'Christmas' originates from Old English, specifically the word 'Cristes mæsse,' where 'Cristes' meant 'Christ's' and 'mæsse' meant 'mass.'

'Cristes mæsse' transformed into the Middle English word 'Cristemasse,' and eventually became the modern English word 'Christmas.'

Initially, it meant 'the mass of Christ,' but over time it evolved into its current meaning of 'the celebration of Christ's birth.'