fever vs feverishness

fever and feverishness both are nouns.

Word	Noun	Adjective	Verb	Adverb
fever	Yes	No	No	No
feverishness	Yes	No	No	No

As nouns, fever and feverishness are synonyms defined as:

fever and feverishness: a rise in the temperature of the body; frequently a symptom of infection

Other synonyms of fever include febricity, febrility, pyrexia.

fever (noun)	feverishness (noun)
a state of nervous excitement	a rise in the temperature of the body; frequently a symptom of infection
a rise in the temperature of the body; frequently a symptom of infection	A state of wildly excited activity or emotion.