death rate vs deathrate

death rate and deathrate both are nouns.

Word	Noun	Adjective	Verb	Adverb
death rate	Yes	No	No	No
deathrate	Yes	No	No	No

As nouns, death rate and deathrate are synonyms defined as:

death rate and deathrate: the ratio of deaths in an area to the population of that area; expressed per 1000 per year

Other synonyms of death rate include fatality rate, mortality, mortality rate.

death rate (noun)	deathrate (noun)
the ratio of deaths in an area to the population of that area; expressed per 1000 per year	the ratio of deaths in an area to the population of that area; expressed per 1000 per year