expectorant vs medicinal drug

expectorant and medicinal drug both are nouns.

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

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

expectorant: a medicine promoting expectoration
medicinal drug: (medicine) something that treats or prevents or alleviates the symptoms of disease

Other hypernyms of expectorant include medicament, medication, medicine.

expectorant (noun)	medicinal drug (noun)
a medicine promoting expectoration	(medicine) something that treats or prevents or alleviates the symptoms of disease