pocketbook vs paperback book

pocketbook and paperback book both are nouns.

Word	Noun	Adjective	Verb	Adverb
pocketbook	Yes	No	No	No
paperback book	Yes	No	No	No

As nouns, paperback book is a hypernym of pocketbook; that is, paperback book is a word with a broader meaning than pocketbook:

Other hypernyms of pocketbook include paper-back book, paperback, soft-cover, soft-cover book, softback, softback book.

pocketbook (noun)	paperback book (noun)
a container used for carrying money and small personal items or accessories (especially by women)	a book with paper covers
pocket-sized paperback book
a pocket-size case for holding papers and paper money
your personal financial means