1. One from whom a person is descended, whether on the fathers or mothers side, at any distance of time; a progenitor; a fore father.
2. (Science: biology) An earlier type; a progenitor; as, this fossil animal is regarded as the ancestor of the horse.
3. One from whom an estate has descended; the correlative of heir.
Origin: oe. Ancestre, auncestre, also ancessour; the first forms fr. OF. Ancestre, f. Ancetre, fr. The L. Nom. Antessor one who goes before; the last form fr. OF. Ancessor, fr. L. Acc. Antecessorem, fr. Antecedere to go before; ante before – cedere to go. See Cede, and cf. Antecessor.