'progenitress' originates from Latin, specifically the word 'progenitrix,' where 'pro-' meant 'forth' and the root 'gignere' (via 'gen-') meant 'to beget' or 'to produce'.

'progenitrix' in Latin passed into Medieval and Early Modern English forms (via Old French/Latin usage) and eventually became the modern English word 'progenitress'.

Initially it meant 'a female begetter' (literally a woman who begets), but over time it evolved into the broader modern sense of 'a female ancestor or female founder of a line or family'.