'truthfully-expressed' originates from the combination of 'truthfully' and 'expressed', where 'truthfully' is derived from 'truth' meaning 'factual' and '-fully' meaning 'in a manner of'. 'Expressed' comes from Latin 'expressus', meaning 'to press out'.

'truthfully-expressed' evolved from the combination of 'truthfully' and 'expressed', which were used separately in Middle English and later combined in modern English.

Initially, it meant 'expressed in a truthful manner', and this meaning has largely remained the same in modern usage.