obstinacy vs rabidity

obstinacy and rabidity both are nouns.

Word	Noun	Adjective	Verb	Adverb
obstinacy	Yes	No	No	No
rabidity	Yes	No	No	No

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

obstinacy: resolute adherence to your own ideas or desires
rabidity: The property of being very extreme, unreasonable, or fanatical in opinion; excessively zealous; comparable to one with rabies.

Other hyponyms of obstinacy include impenitence, impenitency, intransigence, intransigency.

obstinacy (noun)	rabidity (noun)
the trait of being difficult to handle or overcome	unrestrained excitement or enthusiasm
resolute adherence to your own ideas or desires	The property of being very extreme, unreasonable, or fanatical in opinion; excessively zealous; comparable to one with rabies.