obstinate

From this consideration it is that we have derived the custom, in times of war, to punish […] those who are obstinate to defend a place that by the rules of war is not tenable […]

Now it happened that Kasturbai […] had again begun getting haemorrhage, and the malady seemed to be obstinate.

He had the same pile of curly hair, but he was clean-shaven with a heavy, obstinate jowl.