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. Jewish Holidays, 2010-2030 (A.M. 5770-5791) Western Christian Holidays, 2010-2030 12 Steps to a New Year New Year's Resolution to Slim Down? Martin Luther King Speeches Books of the Bible: Old Testament Books in Order ✖ Related Content Daily Word Quiz: contretemps Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language