junk vs scrap

junk and scrap both are nouns.

Word	Noun	Adjective	Verb	Adverb
junk	Yes	No	Yes	No
scrap	Yes	No	Yes	No

As nouns, scrap is a hypernym of junk; that is, scrap is a word with a broader meaning than junk:

Other hypernyms of junk include rubbish, trash.

As verbs, junk and scrap are synonyms defined as:

Other synonyms of junk include trash.

junk (noun)	scrap (noun)
any of various Chinese boats with a high poop and lugsails	the act of fighting; any contest or struggle
the remains of something that has been destroyed or broken up	a small piece of something that is left over after the rest has been used
	a small fragment of something broken off from the whole
	worthless material that is to be disposed of

junk (verb)	scrap (verb)
dispose of (something useless or old)	make into scrap or refuse
	have a disagreement over something
	dispose of (something useless or old)