addict vs drug addict

addict and drug addict both are nouns.

Word	Noun	Adjective	Verb	Adverb
addict	Yes	No	Yes	No
drug addict	Yes	No	No	No

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

Other hyponyms of addict include caffein addict, caffeine addict, junkie, junky, speed freak.

addict (noun)	drug addict (noun)
someone who is physiologically dependent on a substance or activity	a narcotics addict
someone who is so ardently devoted to something that it resembles an addiction

addict (verb)	drug addict (verb)
to cause (someone or oneself) to become dependent (on something, especially a narcotic drug)