infant deathrate vs mortality

infant deathrate and mortality both are nouns.

Word	Noun	Adjective	Verb	Adverb
infant deathrate	Yes	No	No	No
mortality	Yes	No	No	No

As nouns, mortality is a hypernym of infant deathrate; that is, mortality is a word with a broader meaning than infant deathrate:

infant deathrate: the death rate during the first year of life
mortality: the ratio of deaths in an area to the population of that area; expressed per 1000 per year

Other hypernyms of infant deathrate include death rate, deathrate, fatality rate, mortality rate.

infant deathrate (noun)	mortality (noun)
the death rate during the first year of life	the quality or state of being mortal
	the ratio of deaths in an area to the population of that area; expressed per 1000 per year