ETYM Old Eng. ancestre, auncestre, also ancessour; the first forms from Old Fren. ancestre, French ancętre, from the Latin nom. antessor one who goes before.
Someone from whom one is descended (but usually more remote that a grandparent); SYN. ascendant, ascendent, antecedent.

An ancestor; someone from whom one is descended.

A person from whom one is descended; SYN. forbear.
See

1. Person from an earlier time who contributed to the tradition shared by some group.
2. The founder of a family; SYN. father, sire.