I. noun 1. a person, typically one more remote than a grandparent, from whom one is descended • he could trace his ancestors back to James the First.
2. an early type of animal or plant from which others have evolved. • the ancestor of most dolphins is not clear.
• both species of elephant have a common ancestor.
3. an early version of a machine, system, etc. • this instrument is an ancestor of the lute.
– origin Middle English: from Old French ancestre, from Latin antecessor, from antecedere, from ante ‘before’ + cedere ‘go’.