scag vs heroin

scag and heroin both are nouns.

Word	Noun	Adjective	Verb	Adverb
scag	Yes	No	No	No
heroin	Yes	No	No	No

As nouns, heroin is a hypernym of scag; that is, heroin is a word with a broader meaning than scag:

scag: street names for heroin
heroin: a narcotic that is considered a hard drug; a highly addictive morphine derivative; intravenous injection provides the fastest and most intense rush

Other hypernyms of scag include diacetylmorphine.

scag (noun)	heroin (noun)
street names for heroin	a narcotic that is considered a hard drug; a highly addictive morphine derivative; intravenous injection provides the fastest and most intense rush