throwaway vs unwanted

throwaway is a noun but unwanted is not a noun.

Word	Noun	Adjective	Verb	Adverb
throwaway	Yes	Yes	No	No
unwanted	No	Yes	No	No

throwaway (noun)	unwanted (noun)
an advertisement (usually printed on a page or in a leaflet) intended for wide distribution
words spoken in a casual way with conscious under-emphasis
(sometimes offensive) a homeless boy who has been abandoned and roams the streets

throwaway (adjective)	unwanted (adjective)
intended to be thrown away after use	not wanted; not needed
thrown away	not wanted