heroin vs scag

heroin and scag both are nouns.

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

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

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

Other hyponyms of heroin include big H, hell dust, nose drops, skag, smack, thunder.

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