caffeine addict vs addict

caffeine addict and addict both are nouns.

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

As nouns, addict is a hypernym of caffeine addict; that is, addict is a word with a broader meaning than caffeine addict:

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

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