'unvarnished' originates from the prefix 'un-' meaning 'not' and the word 'varnish,' which comes from Middle English 'vernisshen,' from Old French 'vernisser,' from 'vernis' meaning 'varnish.'

'Varnish' changed from the Old French word 'vernis' and eventually became the modern English word 'varnish.'

Initially, 'varnish' meant 'a resinous substance used for coating,' and 'unvarnished' evolved to mean 'not coated or embellished.'