Breadcrumb Home > Dictionary > Index T thermal efficiency: Meaning and Definition of Find definitions for: ther'mal effi'ciency Pronunciation: [key] — Thermodynam. Thermodynam. the ratio of the work output of a heat engine to the heat input expressed in the same units of energy. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. thermal diffusion thermal equilibrium TrendingHere are the facts and trivia that people are buzzing about. Chinese New Year History, Meaning, and Celebrations Current Events This Week: February 2024 Valentine's Day Valentine's Day History Mardi Gras 30 "Charlie and the Chocolate Factory" Quotes ✖ Related Content Daily Word Quiz: supertonic Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language