primogenitor

a person who is several generations earlier in an individual's line of descent <the family held a huge reunion to mark the 200th anniviersary of their primogenitors' arrival in America> Synonyms father, forebear (also forbear), forebearer, forefather, grandfather, ancestor, progenitorRelated Words antecessor, predecessor [archaic]; ancestress, foremother, grandmother, matriarch; grandsire [archaic], patriarch, sire [archaic]; ancestry, antecedents, rootsNear Antonyms children, family, issue, lineage, offspring, posterity, progeny, seed, stock; daughter, heir, inheritor, scion, son, successorAntonyms descendant (also descendent)