'disorganised' originates from the prefix 'dis-' meaning 'not' or 'opposite of' and the word 'organise', which comes from the Latin 'organizare', meaning 'to arrange'.

'organise' changed from the Old French word 'organiser' and eventually became the modern English word 'organise'.

Initially, it meant 'to arrange or set in order', but with the prefix 'dis-', it evolved into its current meaning of 'lacking order'.