Legal Definition of Power of attorney: (a) A written document stating that one appoints another to act in his behalf as an agent, giving him the authority to carry out certain specified acts. (b) A written document giving an attorney the authority to appear in court on someone’s behalf | Find out how the legal definition of Power of Attorney works and why it’s important to have one in place. Learn about the different types, including General, Special, and Healthcare Power of Attorney, and how they can empower someone to act on your behalf. Discover the benefits, such as ensuring your wishes are followed and avoiding conflicts among family members. Consult a legal professional to create a customized Power of Attorney that suits your needs