psychodelic drug vs hallucinogen

psychodelic drug and hallucinogen both are nouns.

Word	Noun	Adjective	Verb	Adverb
psychodelic drug	Yes	No	No	No
hallucinogen	Yes	No	No	No

As nouns, psychodelic drug and hallucinogen are synonyms defined as:

psychodelic drug and hallucinogen: a psychoactive drug that induces hallucinations or altered sensory experiences

Other synonyms of psychodelic drug include hallucinogenic drug, psychedelic drug.

psychodelic drug (noun)	hallucinogen (noun)
a psychoactive drug that induces hallucinations or altered sensory experiences	a psychoactive drug that induces hallucinations or altered sensory experiences