'frequently-proven' originates from the combination of 'frequent' and 'prove', where 'frequent' comes from Latin 'frequentare' meaning 'to visit often', and 'prove' from Latin 'probare' meaning 'to test or demonstrate'.

'frequentare' transformed into the Old French 'frequenter', and 'probare' into the Old French 'prover', eventually becoming the modern English words 'frequent' and 'prove'.

Initially, 'frequent' meant 'to visit often', and 'prove' meant 'to test or demonstrate'. Over time, 'frequently-proven' evolved to mean 'demonstrated as true on many occasions'.