hallucinogen vs psychodelic drug

hallucinogen and psychodelic drug both are nouns.

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

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

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

Other synonyms of hallucinogen include hallucinogenic drug, psychedelic drug.

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