Old Testament vs Zechariah

Old Testament and Zechariah both are nouns.

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

Old Testament (noun)	Zechariah (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 Zechariah which are concerned mainly with the renewal of Israel after the Babylonian Captivity
	a Hebrew minor prophet of the late 6th century BC