'plainchant' originates from the French word 'plain-chant', where 'plain' meant 'simple' and 'chant' meant 'song'.

'plainchant' changed from the Old French word 'plain-chant' and eventually became the modern English word 'plainchant'.

Initially, it meant 'simple song', but over time it evolved into its current meaning of 'a body of chants used in liturgies'.