fieriness vs passion

fieriness and passion both are nouns.

Word	Noun	Adjective	Verb	Adverb
fieriness	Yes	No	No	No
passion	Yes	No	No	No

As nouns, passion is a hypernym of fieriness; that is, passion is a word with a broader meaning than fieriness:

Other hypernyms of fieriness include heat, warmth.

fieriness (noun)	passion (noun)
the heat or the color of fire	the trait of being intensely emotional
a passionate and quick-tempered nature	any object of warm affection or devotion
	a strong feeling or emotion
	a feeling of strong sexual desire
	an irrational but irresistible motive for a belief or action
	something that is desired intensely