The antonyms for the word "more stiffnecked" are humble, meek, yielding, and complaisant. When someone is stiffnecked, they are unyielding or stubbornly resistant to change or new ideas. On the other hand, someone who is humble is willing to learn and open to different perspectives. A meek person is gentle, kind-hearted, and unassuming, making them the opposite of someone who is stiffnecked. Yielding people are flexible and adaptable, able to adjust to different situations as opposed to the rigidity of a stiffnecked individual. Finally, the word complaisant describes someone who is obliging, accommodating, and willing to please, and is the exact opposite of someone who is more stiffnecked.