'unembarrassed' originates from the prefix 'un-' meaning 'not' and the word 'embarrassed', which comes from the French word 'embarrasser', meaning 'to block or hinder'.

'embarrasser' transformed into the English word 'embarrass', and with the addition of the prefix 'un-', it became 'unembarrassed'.

Initially, 'embarrass' meant 'to block or hinder', but over time it evolved to mean 'to cause someone to feel awkward or self-conscious'. 'Unembarrassed' retains the negation of this feeling.