n. That which is self-moving, or has the power of spontaneous movement, but is not conscious.n. Specifically A self-acting machine, or one which is actuated in such a manner as to carry on for some time certain movements without the aid of external impulse.n. A living being acting mechanically or as a mere machine, especially without consciousness; a person or an animal whose actions are purely involuntary or mechanical.n. A person who acts in a monotonous routine manner, without active intelligence, especially without being fully aware of what he is doing.