Anacin III vs pain pill

Anacin III and pain pill both are nouns.

Word	Noun	Adjective	Verb	Adverb
Anacin III	Yes	No	No	No
pain pill	Yes	No	No	No

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

Anacin III: an analgesic for mild pain but not for inflammation; also used as an antipyretic; (Datril, Tylenol, Panadol, Phenaphen, Tempra, and Anacin III are trademarks of brands of acetaminophen tablets)
pain pill: a medicine used to relieve pain

Other hypernyms of Anacin III include analgesic, anodyne, painkiller.

Anacin III (noun)	pain pill (noun)
an analgesic for mild pain but not for inflammation; also used as an antipyretic; (Datril, Tylenol, Panadol, Phenaphen, Tempra, and Anacin III are trademarks of brands of acetaminophen tablets)	a medicine used to relieve pain