breakbone fever vs dengue fever

breakbone fever and dengue fever both are nouns.

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

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

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

Other synonyms of breakbone fever include dandy fever, dengue.

breakbone fever (noun)	dengue 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