addict vs speed freak

addict and speed freak both are nouns.

Word	Noun	Adjective	Verb	Adverb
addict	Yes	No	Yes	No
speed freak	Yes	No	No	No

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

addict: someone who is physiologically dependent on a substance or activity
speed freak: addict who habitually uses stimulant drugs (especially amphetamines)

Other hyponyms of addict include caffein addict, caffeine addict, drug addict, junkie, junky.

addict (noun)	speed freak (noun)
someone who is physiologically dependent on a substance or activity	addict who habitually uses stimulant drugs (especially amphetamines)
someone who is so ardently devoted to something that it resembles an addiction

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