downer vs medicinal drug

downer and medicinal drug both are nouns.

Word	Noun	Adjective	Verb	Adverb
downer	Yes	No	No	No
medicinal drug	Yes	No	No	No

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

downer: a drug that reduces excitability and calms a person
medicinal drug: (medicine) something that treats or prevents or alleviates the symptoms of disease

Other hypernyms of downer include drug of abuse, street drug, medicament, medication, medicine.

downer (noun)	medicinal drug (noun)
a drug that reduces excitability and calms a person	(medicine) something that treats or prevents or alleviates the symptoms of disease