'averruncator' originates from Latin, specifically the verb 'averruncare', where the verb meant 'to ward off or remove (danger or mischief)'.

'averruncator' changed from Medieval/Early Modern English usage influenced by Latin 'averruncare' and appeared in English as a rare noun meaning 'one who averruncates' (i.e., wards off misfortune).

Initially it meant 'one who wards off or removes danger/mischief' in contexts of ritual or charm; this basic sense has been preserved but the word became rare and mostly historical.