pain pill vs medication

pain pill and medication both are nouns.

Word	Noun	Adjective	Verb	Adverb
pain pill	Yes	No	No	No
medication	Yes	No	No	No

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

pain pill: a medicine used to relieve pain
medication: (medicine) something that treats or prevents or alleviates the symptoms of disease

Other hypernyms of pain pill include medicament, medicinal drug, medicine.

pain pill (noun)	medication (noun)
a medicine used to relieve pain	the act of treating with medicines or remedies
	(medicine) something that treats or prevents or alleviates the symptoms of disease