'unobligated' originates from the prefix 'un-' meaning 'not' and the word 'obligated' from Latin 'obligatus', past participle of 'obligare', meaning 'to bind'.

'obligatus' transformed into the Old French word 'obliger', and eventually became the modern English word 'obligate', with 'un-' added to form 'unobligated'.

Initially, it meant 'not bound by a legal or moral duty', and this meaning has largely remained the same in modern usage.