The child was so stubborn that he wouldn't listen to anyone's advice.

stubborn 是形容词，意思是"固执的、倔强的"，形容一个人坚持己见、不愿意改变想法或听从他人意见的性格特点。这个词常带有轻微的贬义，表示这种固执可能是不合理的。