primogenitor

[ prahy-muh-jen-i-ter ]
/ ˌpraɪ məˈdʒɛn ɪ tər /

noun

a first parent or earliest ancestor: Adam and Eve are the primogenitors of the human race.
a forefather or ancestor.

Origin of primogenitor

1645–55; < Late Latin prīmōgenitor ancestor, equivalent to Latin prīmō at first + genitor genitor

British Dictionary definitions for primogenitor

primogenitor
/ (ˌpraɪməʊˈdʒɛnɪtə) /

noun

a forefather; ancestor
an earliest parent or ancestor, as of a race

Word Origin for primogenitor

C17: alteration of progenitor after primogeniture