'sophistical' originates from Latin, specifically the word 'sophisticus', which in turn comes from the Greek 'sophistikos' derived from 'sophos' meaning 'wise' or 'skilled'.

'sophistical' changed from the Old French word 'sophistique' (via Latin 'sophisticus' from Greek 'sophistikos' / 'sophisma') and eventually became the modern English word 'sophistical'.

Initially, it meant 'characteristic of a sophist; clever or subtle (in argument)', but over time it evolved to the current primary meaning of 'deceptively plausible; fallacious'.