fervency vs fervor

fervency and fervor both are nouns.

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

As nouns, fervency and fervor are synonyms defined as:

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

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