proavitus

prŏăvītus, a, um, adj. [proavus],

of or belonging to a great-grandfather , or to one's ancestors , ancestral (poet.): regna, inherited from his forefathers , Ov. M. 13, 416: rura, Stat. S. 4, 4, 83: potentia, Sil. 16, 254: medicamina didicit, id. 5, 366: facta, id. 11, 88.