顽固 (wán gù): ดื้อรั้น

He stubbornly refused to admit his mistake, even with the evidence right in front of him.

This child is very stubborn; no matter how his parents try to persuade him, he won't change his mind.

Her stubborn personality made her refuse to compromise in the negotiation, and she ultimately lost the cooperation opportunity.

Despite the doctor's repeated warnings, he stubbornly insisted on smoking, and as a result, his condition worsened.