/ Dictionary / Index T Third International: Meaning and Definition of Find definitions for: Third' Interna'tional Pronunciation: [key] an international organization (1919–43), founded in Moscow, uniting Communist groups of various countries and advocating the attainment of their ends by violent revolution. Also calledCf.(def. 6). Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. third house third law of motion Related Content Daily Word Quiz: procrastinate Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language