bullheadedness vs obstinacy

bullheadedness and obstinacy both are nouns.

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

As nouns, bullheadedness and obstinacy are synonyms defined as:

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

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

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