The term "stiff-necked" is commonly used to describe a person who is stubborn, unyielding, and inflexible. Antonyms for this term would include words like adaptable, flexible, open-minded, and cooperative. An adaptable person is one who can easily adjust to new situations and ideas. A flexible person is one who is capable of bending and changing their opinions or beliefs. An open-minded person is receptive to diverse thoughts and opinions. A cooperative person is one who is willing to work with others toward a common goal. All these antonyms for "more stiff-necked" indicate a person who is willing to learn, grow, and compromise rather than being obstinate and rigid.