dandy fever vs breakbone fever

dandy fever and breakbone fever both are nouns.

Word	Noun	Adjective	Verb	Adverb
dandy fever	Yes	No	No	No
breakbone fever	Yes	No	No	No

As nouns, dandy fever and breakbone fever are synonyms defined as:

dandy fever and breakbone fever: an infectious disease of the tropics transmitted by mosquitoes and characterized by rash and aching head and joints

Other synonyms of dandy fever include dengue, dengue fever.

dandy fever (noun)	breakbone fever (noun)
an infectious disease of the tropics transmitted by mosquitoes and characterized by rash and aching head and joints	an infectious disease of the tropics transmitted by mosquitoes and characterized by rash and aching head and joints