Breadcrumb Home > Dictionary > Index U understratum: Meaning and Definition of Find definitions for: un•der•stra•tum Pronunciation: (un'dur-strā"tum, -strat"um), [key] — pl. -stra•ta -strat•ums. a substratum. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. understrapper understrength 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: anomie Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language