1. Anyone from whom someone else is directly descended; especially, somebody more distant than a grandparent; such as, grandparents, great-grandparents; great-great-grandparents, etc.: Jennifer told her friends that some of her ancestors lived when George Washington was president of the U.S.
2. An animal or plant from which a species has evolved.
3. A device that was an earlier form of a modern invention or was used as a basis for developing it; such as, an object, idea, style, or occurrence serving as a prototype, forerunner, or inspiration to a later one.
4. A person from whom an heir derives an inheritance.
5. Etymology: from Old French ancestre or Modern French ancêtre which is from Late Latin antecessor, "predecessor"; literally, "foregoer"; from Latin antecessus, past participle of antecedere, "to precede", from ante-, "before" + cedere, "to go, to give way".