'unworldly' originates from the prefix 'un-' meaning 'not' and the word 'worldly,' which comes from Old English 'woruldlic,' where 'woruld' meant 'world' and '-lic' meant 'like.'

'woruldlic' transformed into the Middle English word 'worldlich,' and eventually became the modern English word 'worldly,' with 'un-' added to form 'unworldly.'

Initially, it meant 'not of this world,' but over time it evolved into its current meaning of 'lacking awareness of worldly matters.'