'acheer' originates from Middle English, specifically the word 'achere,' where 'a-' meant 'on' and 'chere' meant 'face or countenance.'

'achere' transformed into the modern English word 'acheer' through gradual phonetic changes.

Initially, it meant 'a cheerful face or expression,' but over time it evolved into its current meaning of 'a state of cheerfulness or joy.'