backed vs hardcover

backed is not a noun while hardcover is a noun.

Word	Noun	Adjective	Verb	Adverb
backed	No	Yes	No	No
hardcover	Yes	Yes	No	No

backed (noun)	hardcover (noun)
	a book with cardboard or cloth or leather covers

backed (adjective)	hardcover (adjective)
having a back or backing, usually of a specified type	having a hard back or cover
used of film that is coated on the side opposite the emulsion with a substance to absorb light