Other forms: ancestors
An ancestor came before. Your grandmother's grandmother and any relative before her is one of your ancestors.
Ante-, a common Latin prefix, means "before." Cedere is Latin for "to go." So, an ancestor is someone who has gone before us. Evolutionary biologists have advanced the theory that all life on earth descends from a common ancestor. Ancestor can also mean "prototype" or "forerunner." The abacus is a distant ancestor of today's supercomputers.