New World monkey vs platyrrhine

New World monkey and platyrrhine both are nouns.

Word	Noun	Adjective	Verb	Adverb
New World monkey	Yes	No	No	No
platyrrhine	Yes	Yes	No	No

As nouns, New World monkey and platyrrhine are synonyms defined as:

New World monkey and platyrrhine: hairy-faced arboreal monkeys having widely separated nostrils and long usually prehensile tails

Other synonyms of New World monkey include platyrrhinian.

New World monkey (noun)	platyrrhine (noun)
hairy-faced arboreal monkeys having widely separated nostrils and long usually prehensile tails	hairy-faced arboreal monkeys having widely separated nostrils and long usually prehensile tails

New World monkey (adjective)	platyrrhine (adjective)
	of or related to New World monkeys having nostrils far apart or to people with broad noses