feverishness vs fervor

feverishness and fervor both are nouns.

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

As nouns, fervor is a hypernym of feverishness; that is, fervor is a word with a broader meaning than feverishness:

Other hypernyms of feverishness include excitation, excitement, fervour, inflammation.

feverishness (noun)	fervor (noun)
a rise in the temperature of the body; frequently a symptom of infection	feelings of great warmth and intensity
A state of wildly excited activity or emotion.	the state of being emotionally aroused and worked up