'refutability' originates from Latin via English formation: from the Latin verb 'refutare' (entered English through Late Latin/Old French), where the prefix 're-' meant 'back' and the root related to 'futare'/'fut-' carried the sense of 'repel/drive back'; in English it was formed by adding the noun-forming suffix '-ability' to 'refute'/'refutable'.

'refutare' in Latin (meaning 'to repel, drive back') passed into Medieval/Old French as forms like 'refuter' and then into Middle English as 'refuten'/'refute'; from English 'refute' the adjective 'refutable' and the abstract noun 'refutability' were later formed by adding '-able' and '-ability'.

Initially, the root meant roughly 'to repel or drive back'; over time the sense narrowed in English to 'to prove incorrect or disprove', and 'refutability' developed to mean 'the capacity of a claim or theory to be disproved'.