yo·him·bine (y?-h?m?b?n?)n. An alkaloid, C21H26N2O3, that is derived from the bark of a tree, Pausinystalia johimbe, and is an alpha-blocker drug used in the form of its hydrochloride as a mydriatic, a treatment for erectile dysfunction, and formerly as an aphrodisiac. [New Latin yohimbe, former specific epithet (of Cameroonian Bantu origin; akin to Douala djombe, the tree from which yohimbine is derived) + -ine.]American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.yohimbine (j???h?mbi?n) n (Elements & Compounds) an alkaloid found in the bark of the tree Corynanthe yohimbe. It is used in medicine as an adrenergic blocking agent. Formula: C21H26N2O3[C19: from Bantu yohimbé a tropical African tree + -ine1]Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014yo?him?bine (yo??h?m bin) n. an extract of the bark of the yohimbe or rauwolfia tree, used medicinally to oppose the effects of epinephrine. [1895?1900; yohimb (e) + -ine2; perhaps orig. formed in German] Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.