codeine vs opiate

codeine and opiate both are nouns.

Word	Noun	Adjective	Verb	Adverb
codeine	Yes	No	No	No
opiate	Yes	No	No	No

As nouns, opiate is a hypernym of codeine; that is, opiate is a word with a broader meaning than codeine:

codeine: derivative of opium; used as an antitussive (to relieve coughing) and an analgesic (to relieve pain)
opiate: a narcotic drug that contains opium or an opium derivative

Other hypernyms of codeine include analgesic, anodyne, pain pill, painkiller, antitussive.

codeine (noun)	opiate (noun)
derivative of opium; used as an antitussive (to relieve coughing) and an analgesic (to relieve pain)	a narcotic drug that contains opium or an opium derivative