Breadcrumb Home > Dictionary > Index B black arm: Meaning and Definition of Find definitions for: black' arm" Pronunciation: [key] — Plant Pathol. Plant Pathol. a type or phase of bacterial blight of cotton, characterized by black, elongated lesions on the stem and branches, caused by a bacterium, Xanthomonas malvacearum. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Black Angus black art 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: ennui Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language