Breadcrumb Home > Dictionary > Index P prothorax: Meaning and Definition of Find definitions for: pro•tho•rax Pronunciation: (prō-thôr'aks, -thōr'-), [key] — pl. -tho•rax•es, -tho•ra•ces the anterior division of the thorax of an insect, bearing the first pair of legs. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: prothorax (Thesaurus) prothoracic gland prothrombin 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: fatuous Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language