'demise' originates from Old French (Old French 'demise' / 'demission'), ultimately from Medieval Latin 'dimissio', where the prefix 'di-' or 'dis-' meant 'away' and Latin 'mittere' meant 'to send'.

'demise' changed from Medieval Latin 'dimissio' and Old French 'demise'/'demission' and eventually became the modern English word 'demise'.

Initially it meant 'a sending away' or 'dismissal' (often a legal transfer); over time it also came to mean 'death' or 'the end'.