sleeping pill vs soporific

sleeping pill and soporific both are nouns.

Word	Noun	Adjective	Verb	Adverb
sleeping pill	Yes	No	No	No
soporific	Yes	Yes	No	No

As nouns, soporific is a hypernym of sleeping pill; that is, soporific is a word with a broader meaning than sleeping pill:

sleeping pill: a soporific drug in the form of a pill (or tablet or capsule)
soporific: a drug that induces sleep

Other hypernyms of sleeping pill include lozenge, pill, tab, tablet, hypnotic.

sleeping pill (noun)	soporific (noun)
a soporific drug in the form of a pill (or tablet or capsule)	a drug that induces sleep

sleeping pill (adjective)	soporific (adjective)
	sleep inducing
	inducing mental lethargy