Any of certain anthropoid primates of Africa and Asia (also called catarrhines), as distinguished from the New World monkeys (platyrrhines). Catarrhines are generally distinguished from platyrrhines in having a narrow nose, narrow septum, close-set nostrils directed forward or down, bony ear passages, two premolars in each half of each jaw, a nonprehensile tail (if any), and hard patches of bare skin (ischial callosities) on the buttocks. The terms Old World monkey and catarrhine usually apply only to members of the families Cercopithecidae (monkeys with cheek pouches: guenons, baboons, and others) and Colobidae (leaf monkeys) but may also include the families Hylobatidae (gibbons), Pongidae (apes), and Hominidae (human beings). See also colobus monkey; proboscis monkey; vervet monkey
The Old World refers to Europe Europeans referred to their region as the Old World in contrast to the New Worldwhich had been recently discovered by European explorers (see New World)
the regions of the world that were known to Europeans before the discovery of the Americas of or relating to the Old World (especially Europe); "Old World hawks"; "Old World monkeys