The word "bull-headed" is used to describe someone who is stubborn and refuses to change their opinion or behavior. However, there are several antonyms for this term. One could describe someone who is flexible and adaptable as "open-minded" or "accommodating". Similarly, someone who is willing to compromise and negotiate could be referred to as "conciliatory" or "cooperative". Additionally, a person who is willing to listen to different perspectives and consider alternative ideas could be called "perceptive" or "receptive". Overall, there are many ways to describe the opposite of a bull-headed individual, emphasizing the importance of constructive collaboration and a willingness to compromise.