ardor vs ardour

ardor and ardour both are nouns.

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

As nouns, ardor and ardour are synonyms defined as:

As nouns, ardor and ardour are synonyms defined as:

ardor and ardour: a feeling of strong eagerness (usually in favor of a person or cause)

Other synonyms of ardor include elan, zeal.

As nouns, ardor and ardour are synonyms defined as:

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

ardor (noun)	ardour (noun)
intense feeling of love	intense feeling of love
a feeling of strong eagerness (usually in favor of a person or cause)	a feeling of strong eagerness (usually in favor of a person or cause)
feelings of great warmth and intensity	feelings of great warmth and intensity