ua·ka·ri (wä-kä?r?)n. pl. ua·ka·ris Either of two medium-sized fruit-eating arboreal monkeys (Cacajao calvus or C. melanocephalus) of Amazonia, having a nearly bare stomach with long hair on the shoulders and upper back and a short bushy nonprehensile tail.[Of Tupian origin; akin to Amazonian Língua Geral (Tupí-based lingua franca of the Amazon River region) acari.]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.uakari (wæ?kær?) n (Animals) a monkey of the genus Cacajao with a bald red face and long reddish fur, found in the north-western Amazon basinCollins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014