adjective
obdurate
AHB-duh-rut/ˈɑːbdərət/
Stubbornly refusing to change an opinion or course of action.
Despite clear evidence, he remains obdurate and refuses to reconsider.

Etymology
The image is of becoming hard against an influence. Applied especially to a hardened heart, it came to describe someone who resists persuasion or refuses to change course.
In context
Valancy had wanted her old Free Methodist man, but Roaring Abel was obdurate. He was a Presbyterian and no one but a Presbyterian minister should bury _his_ daughter.
More examples
- The obdurate landlord rejects every request to lower the rent.
- She is obdurate in her opposition to the new policy.
- Even his closest friends cannot persuade him to abandon his obdurate stance.
Forms
obdurate
obduracy noun — Stubborn refusal to change one's position.
obdurately adverb — In a stubbornly unyielding manner.
Similar words
- stubborn
- More everyday and broader; can also describe things resisting change.
- intransigent
- Emphasizes refusal to compromise, especially in disputes or negotiations.
- adamant
- Emphasizes firm conviction without necessarily suggesting unreasonable resistance.