Know how to use "fewer" and "less"? Find out.
c.1300, ancestre, antecessour, from Old French ancestre (12c., Modern French ancêtre), from Late Latin antecessor "predecessor," literally "foregoer," agent noun from past participle stem of Latin antecedere "to precede," from ante- "before" (see ante) + cedere "to go" (see cede). Current form from early 15c. Feminine form ancestress recorded from 1570s.