'apodixis' originates from Ancient Greek, specifically the word 'ἀπόδειξις' (apodíxis), where the prefix 'apo-' meant 'away, from' and the root 'deik-' (from 'deiknynai') meant 'to show'.

'apodixis' passed into Late Latin and Medieval scholarly Latin (via forms such as 'apodixis'/'apodictio') and then into English usage through Latin and scholarly writings, becoming the modern English technical term 'apodixis'.

Initially it meant 'a showing forth, demonstration', and over time it has retained the core sense of 'demonstration' or 'conclusive proof', though its use became more specialized and rare in modern English.