Old Testament vs Aggeus

Old Testament and Aggeus both are nouns.

Word	Noun	Adjective	Verb	Adverb
Old Testament	Yes	No	No	No
Aggeus	Yes	No	No	No

Old Testament (noun)	Aggeus (noun)
the collection of books comprising the sacred scripture of the Hebrews and recording their history as the chosen people; the first half of the Christian Bible	an Old Testament book telling the prophecies of Haggai which are concerned mainly with rebuilding the temples after the Babylonian Captivity
	a Hebrew minor prophet, the first of three post-exile prophets from the Neo-Babylonian Exile of the House of Judah