fervency vs fervidness

fervency and fervidness both are nouns.

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

As nouns, fervency and fervidness are synonyms defined as:

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

fervency (noun)	fervidness (noun)
feelings of great warmth and intensity	feelings of great warmth and intensity