three-day measles vs German measles

three-day measles and German measles both are nouns.

Word	Noun	Adjective	Verb	Adverb
three-day measles	Yes	No	No	No
German measles	Yes	No	No	No

As nouns, three-day measles and German measles are synonyms defined as:

three-day measles and German measles: a contagious viral disease that is a milder form of measles lasting three or four days; can be damaging to a fetus during the first trimester

Other synonyms of three-day measles include epidemic roseola, rubella.

three-day measles (noun)	German measles (noun)
a contagious viral disease that is a milder form of measles lasting three or four days; can be damaging to a fetus during the first trimester	a contagious viral disease that is a milder form of measles lasting three or four days; can be damaging to a fetus during the first trimester