Africa vs Great Rift Valley

Africa and Great Rift Valley both are nouns.

Word	Noun	Adjective	Verb	Adverb
Africa	Yes	No	No	No
Great Rift Valley	Yes	No	No	No

Africa (noun)	Great Rift Valley (noun)
the second largest continent; located to the south of Europe and bordered to the west by the South Atlantic and to the east by the Indian Ocean	(geology) a depression in southwestern Asia and eastern Africa; extends from the valley of the Jordan River to Mozambique; marked by geological faults