fervor vs ardour

fervor and ardour both are nouns.

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

As nouns, fervor and ardour are synonyms defined as:

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

fervor (noun)	ardour (noun)
feelings of great warmth and intensity	intense feeling of love
the state of being emotionally aroused and worked up	a feeling of strong eagerness (usually in favor of a person or cause)
	feelings of great warmth and intensity