'unfriendly' originates from Old English, specifically the word 'unfrēondlīc', where 'un-' meant 'not' and 'frēondlīc' meant 'friendly'.

'unfrēondlīc' transformed into the Middle English word 'unfrendly', and eventually became the modern English word 'unfriendly'.

Initially, it meant 'not friendly', and this meaning has largely remained the same in modern usage.