obstinacy vs pigheadedness

obstinacy and pigheadedness both are nouns.

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

As nouns, obstinacy and pigheadedness are synonyms defined as:

obstinacy and pigheadedness: resolute adherence to your own ideas or desires

Other synonyms of obstinacy include bullheadedness, obstinance, self-will, stubbornness.

obstinacy (noun)	pigheadedness (noun)
the trait of being difficult to handle or overcome	resolute adherence to your own ideas or desires
resolute adherence to your own ideas or desires