'contradictable' originates from English, specifically formed from the verb 'contradict' plus the adjectival suffix '-able' (the suffix ultimately from Old French/Latin), where 'contra-' meant 'against' and Latin 'dicere' meant 'to say', and Latin '-abilis' meant 'able to'.

'contradict' changed from Latin 'contradicere' (contra- + dicere) into Medieval/Old French forms such as 'contredire' or Medieval Latin usage, then into Middle English as 'contradict'; the adjective was later formed by adding the suffix '-able' (from Old French '-able', from Latin '-abilis') to yield 'contradictable'.

Initially, the root meant 'to speak against' or 'to say against'; over time it evolved to mean 'to deny or assert the opposite', and with the suffix '-able' it came to mean 'able to be contradicted' (i.e., capable of being denied or refuted).