put away vs junk

put away is not a noun while junk is a noun.

Word	Noun	Adjective	Verb	Adverb
put away	No	No	Yes	No
junk	Yes	No	Yes	No

As verbs, junk is a hyponym of put away; that is, junk is a word with a more specific, narrower meaning than put away:

put away (noun)	junk (noun)
	any of various Chinese boats with a high poop and lugsails
	the remains of something that has been destroyed or broken up

put away (verb)	junk (verb)
turn away from and put aside, perhaps temporarily	dispose of (something useless or old)
eat up; usually refers to a considerable quantity of food
kill gently, as with an injection
place in a place where something cannot be removed or someone cannot escape
stop using
throw or cast away
lock up or confine, in or as in a jail