Being obdurate means being stubborn, unyielding, and inflexible. There are several synonyms that can be used to describe this trait, such as adamant, immovable, resolute, unrelenting, inexorable, and hardheaded. These words convey an unwavering persistence in one's beliefs or actions, despite any opposition or reasoning that may be presented. Other synonyms that could be used for "be obdurate" might include pigheaded, obstinate, stubborn-minded, and willful. These words all paint a picture of someone who refuses to budge in their opinions or behaviors, even if it means going against common sense or causing harm to themselves or others.