'allhallows' originates from Old English, specifically the words 'ealra halgena mæsse', where 'ealra' meant 'all' and 'halgena' meant 'saints'.

'ealra halgena mæsse' transformed into the Middle English word 'alhalowmesse', and eventually became the modern English word 'allhallows'.

Initially, it meant 'the mass of all saints', but over time it evolved into its current meaning of 'All Saints' Day'.