'unintentionally-done' originates from the word 'unintentional,' which is derived from the prefix 'un-' meaning 'not' and 'intentional,' which comes from Latin 'intentio,' meaning 'a stretching out.'

'unintentional' evolved from the Latin word 'intentio' through Old French 'intention' and eventually became the modern English word 'intentional.' The prefix 'un-' was added to form 'unintentional.'

Initially, 'intentional' meant 'a stretching out or purpose,' but over time, 'unintentional' evolved to mean 'not done on purpose.'