'unworried' originates from the prefix 'un-' meaning 'not' and the word 'worried', which comes from Old English 'wyrgan', meaning 'to strangle'.

'worried' changed from the Old English word 'wyrgan' and eventually became the modern English word 'worried'.

Initially, 'worried' meant 'to strangle', but over time it evolved into its current meaning of 'anxious or concerned'.