Hebrews vs Old Testament

Hebrews and Old Testament both are nouns.

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

Hebrews (noun)	Old Testament (noun)
a New Testament book traditionally included among the epistle of Saint Paul but now generally considered not to have been written by him	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
the ethnic group claiming descent from Abraham and Isaac (especially from Isaac's son Jacob); the nation whom God chose to receive his revelation and with whom God chose to make a covenant (Exodus 19)