Breadcrumb Home > Dictionary > Index D deci-: Meaning and Definition of Find definitions for: deci- Pronunciation: [key] a combining form meaning “tenth,” used in words denoting units of the metric system (deciliter); on this model, extended to other systems (decibel). Cf. deca-. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. dechlorinate decibar TrendingHere are the facts and trivia that people are buzzing about. Biographies: Notable Jewish Religious Leaders Current Events This Week: September 2023 Hispanic Population and the 2010 U.S. Census 50 Spookiest Halloween Quotes Preamble of the United Nations Charter The Jewish Calendar ✖ Related Content Daily Word Quiz: effete Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language