'argumentum' originates from Latin, specifically the word 'argumentum', where the root 'argu-' (from 'arguere') meant 'to make clear, to prove.'

'argumentum' was used in Classical Latin to mean 'proof' or 'evidence'; it continued in Medieval Latin and was preserved in scholarly and legal contexts, later appearing in English technical usage often within Latin phrases.

Initially it meant 'proof' or 'evidence' in Latin; over time its usage in English has come to mean 'an argument or piece of reasoning,' while the original sense of 'proof' is still retained in some scholarly contexts.