passionateness vs ardor

passionateness and ardor both are nouns.

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

As nouns, ardor is a hyponym of passionateness; that is, ardor is a word with a more specific, narrower meaning than passionateness:

Other hyponyms of passionateness include infatuation, abandon, wildness, ardour, fervency, fervidness, fervor, fervour, fire, storminess.

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