Ancestor \An"ces*tor\, n. [OE. ancestre, auncestre, also ancessour; the first forms fr. OF. ancestre, F. anc[^e]tre, 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.]

1. One from whom a person is descended, whether on the father's or mother's side, at any distance of time; a progenitor; a fore father.

2. (Biol.) An earlier type; a progenitor; as, this fossil animal is regarded as the ancestor of the horse.

3. (Law) One from whom an estate has descended; -- the correlative of heir.

Source: Webster's Revised Unabridged Dictionary (1913)