Definition of "rhesus monkey" []

• A brownish monkey (Macaca mulatta) of India, used extensively in biological and medical research. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• ""No. I've been trying them all-guinea pigs, dogs, cats, rats, even a rhesus monkey I got in town."