'antilogism' originates from Greek (via Late Latin), specifically the word 'antilogismos', where 'anti-' meant 'against' and 'logismos' meant 'reasoning' or 'calculation'.

'antilogism' changed from Late Latin 'antilogismus' (and Medieval Latin forms) and eventually became the modern English word 'antilogism'.

Initially it meant 'an argument offered against another argument'; over time the sense broadened in some uses to mean simply 'a contradiction' or 'something contrary to reason'.