mescaline vs psychedelic drug

mescaline and psychedelic drug both are nouns.

Word	Noun	Adjective	Verb	Adverb
mescaline	Yes	No	No	No
psychedelic drug	Yes	No	No	No

As nouns, psychedelic drug is a hypernym of mescaline; that is, psychedelic drug is a word with a broader meaning than mescaline:

mescaline: the hallucinatory alkaloid that is the active agent in mescal buttons
psychedelic drug: a psychoactive drug that induces hallucinations or altered sensory experiences

Other hypernyms of mescaline include hallucinogen, hallucinogenic drug, psychodelic drug.

mescaline (noun)	psychedelic drug (noun)
the hallucinatory alkaloid that is the active agent in mescal buttons	a psychoactive drug that induces hallucinations or altered sensory experiences