monomania vs passion

monomania and passion both are nouns.

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

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

Other hypernyms of monomania include cacoethes, mania.

monomania (noun)	passion (noun)
a mania restricted to one thing or idea	the trait of being intensely emotional
	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