Old Testament vs Cain

Old Testament and Cain both are nouns.

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

Old Testament (noun)	Cain (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	(Old Testament) Cain and Abel were the first children of Adam and Eve born after the Fall of Man; Cain killed Abel out of jealousy and was exiled by God