'verifiably' originates from Latin via Old French, specifically the Latin word 'verificare', where 'verus' meant 'true' and 'facere' meant 'to make'.

'verificare' changed into Old French 'verifier' and Middle English 'verify', from which the adjective 'verifiable' was formed in Modern English and then the adverb 'verifiably' developed.

Initially, it meant 'to make true' (to confirm or establish truth), and over time it evolved into the modern sense related to 'being able to be checked or proven'; 'verifiably' now means 'in a way that can be verified'.