junky vs opium addict

junky and opium addict both are nouns.

Word	Noun	Adjective	Verb	Adverb
junky	Yes	No	No	No
opium addict	Yes	No	No	No

As nouns, opium addict is a hyponym of junky; that is, opium addict is a word with a more specific, narrower meaning than junky:

Other hyponyms of junky include cocaine addict, binger, crack addict, heroin addict, opium taker, withdrawer.

junky (noun)	opium addict (noun)
a narcotics addict	someone addicted to opium
someone who is so ardently devoted to something that it resembles an addiction