'anteact' originates from Latin elements, specifically the prefix 'ante-' and the verb root 'agere'/'actus', where 'ante-' meant 'before' and 'agere' meant 'to do, to act'.

'anteact' was formed in English from Latin components (via Late or Medieval Latin formations combining 'ante-' + forms of 'agere') and appeared in Early Modern English usage as a compound meaning 'to act before'.

Initially, it meant 'to act before' in a literal sense; over time the word remained close to that meaning but became rare/archaic in modern usage.