Old World vs Afro-Eurasia

Old World and Afro-Eurasia both are nouns.

Word	Noun	Adjective	Verb	Adverb
Old World	Yes	No	No	No
Afro-Eurasia	Yes	No	No	No

As nouns, Old World and Afro-Eurasia are synonyms defined as:

Old World and Afro-Eurasia: regions of the world such as Africa, Europe and Asia that were known to Europeans before the discovery of the Americas which they called the New World

Other synonyms of Old World include Afroeurasia, Eurafrasia.

Old World (noun)	Afro-Eurasia (noun)
regions of the world such as Africa, Europe and Asia that were known to Europeans before the discovery of the Americas which they called the New World	regions of the world such as Africa, Europe and Asia that were known to Europeans before the discovery of the Americas which they called the New World