/an"ses teuhr/ or, esp. Brit., /-seuh steuhr/ , 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.
[ 1250-1300; ME ancestre t developed between s and r ) antecessor ANTECESSOR ]