Breadcrumb Home > Dictionary > Index H heat reservoir: Meaning and Definition of Find definitions for: heat' res"ervoir Pronunciation: [key] — Thermodynam. Thermodynam. a hypothetical body of infinitely large mass capable of absorbing or rejecting unlimited quantities of heat without undergoing appreciable changes in temperature, pressure, or density. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. heat rash heat-seal 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: meritocracy Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language