aminopyrine vs pain pill

aminopyrine and pain pill both are nouns.

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

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

aminopyrine: a white crystalline substance used as an analgesic and antipyretic
pain pill: a medicine used to relieve pain

Other hypernyms of aminopyrine include analgesic, anodyne, painkiller.

aminopyrine (noun)	pain pill (noun)
a white crystalline substance used as an analgesic and antipyretic	a medicine used to relieve pain