- Of or designating the New World monkeys, distinguished from the Old World monkeys by widely separated nostrils that generally open to the side. (adjective)
- Having a broad flat nose. (adjective)
- A platyrrhine monkey. (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.