crib death vs sleep apnea

crib death and sleep apnea both are nouns.

Word	Noun	Adjective	Verb	Adverb
crib death	Yes	No	No	No
sleep apnea	Yes	No	No	No

As nouns, sleep apnea is a hypernym of crib death; that is, sleep apnea is a word with a broader meaning than crib death:

crib death: sudden and unexpected death of an apparently healthy infant during sleep
sleep apnea: apnea that occurs during sleep

Other hypernyms of crib death include death.

crib death (noun)	sleep apnea (noun)
sudden and unexpected death of an apparently healthy infant during sleep	apnea that occurs during sleep