Pronunciation: (an'ses-tur or, esp. Brit., -su-stur),[key] —n. 1. a person from whom one is descended; forebear; progenitor.
2. Biol.the actual or hypothetical form or stock from which an organism has developed or descended.
3. an object, idea, style, or occurrence serving as a prototype, forerunner, or inspiration to a later one: The balloon is an ancestor of the modern dirigible. 4. a person who serves as an influence or model for another; one from whom mental, artistic, spiritual, etc., descent is claimed: a philosophical ancestor. 5. Law.a person from whom an heir derives an inheritance.