A multicellular organism of the kingdom Animalia, differing from plants in certain typical characteristics such as capacity for locomotion, nonphotosynthetic metabolism, pronounced response to stimuli, restricted growth, and fixed bodily structure. An animal organism other than a human, especially a mammal. A person who behaves in a bestial or brutish manner. A human considered with respect to his or her physical, as opposed to spiritual, nature. A person having a specified aptitude or set of interests: "that rarest of musical animals, an instrumentalist who is as comfortable on a podium with a stick as he is playing his instrument\u201d ( Lon Tuck). Relating to, characteristic of, or derived from an animal or animals: animal fat. Relating to the physical as distinct from the spiritual nature of people: animal instincts and desires.