'agonise' originates from Greek, specifically the word 'agōnizesthai,' where 'agōn' meant 'contest' or 'struggle.'

'agōnizesthai' transformed into the Late Latin word 'agonizare,' and eventually became the modern English word 'agonise' through Old French 'agoniser.'

Initially, it meant 'to contend in a struggle or contest,' but over time it evolved into its current meaning of 'to suffer mental anguish.'