fervidness vs fervor

fervidness and fervor both are nouns.

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

As nouns, fervidness and fervor are synonyms defined as:

Other synonyms of fervidness include ardor, ardour, fervency, fervour, fire.

fervidness (noun)	fervor (noun)
feelings of great warmth and intensity	feelings of great warmth and intensity
	the state of being emotionally aroused and worked up