'ague' originates from Middle English, specifically the word 'ague,' which came from Old French 'ague,' derived from Latin 'acuta,' meaning 'sharp fever.'

'acuta' transformed into the Old French word 'ague,' and eventually became the modern English word 'ague' through Middle English.

Initially, it meant 'sharp fever,' but over time it evolved into its current meaning of 'a fever with chills.'