Breadcrumb Home > Dictionary > Index I index fossil: Meaning and Definition of Find definitions for: in'dex fos"sil Pronunciation: [key] — Geol., Paleontol. Geol.,Paleontol. a widely distributed fossil, of narrow range in time, regarded as characteristic of a given geological formation, used esp. in determining the age of related formations. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. index finger index fund 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: catalpa Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language