Breadcrumb Home > Dictionary > Index Z zillion: Meaning and Definition of Find definitions for: zil•lion Pronunciation: (zil'yun), [key] — n., pl. adj. -lions, -lion, —n. an extremely large, indeterminate number. —adj. of, pertaining to, or amounting to a zillion. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: zillion (Thesaurus) zillah zillionaire TrendingHere are the facts and trivia that people are buzzing about. Hanukkah Origins of the Christmas Holiday Jewish Holidays, 2010-2030 (A.M. 5770-5791) Western Christian Holidays, 2010-2030 Krampus: The Christmas Devil Kwanzaa ✖ Related Content Daily Word Quiz: tintinnabulation Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language