n. The process or state of acting or of being active, as opposed to rest; change of which the cause lies within the subject; activity; active exertion; energy manifested in outward acts, as contrasted with contemplation, speculation, speaking, or writing: as, a man of action.n. An event considered as predicated of its cause; an act, usually in a complex or an inclusive sense; that which is done about or in relation to anything; a specific performance, proceeding, or course of conduct: as, a good or a bad action; actions speak louder than words; the action of a deliberative body.n. An exertion of power or force; the real relation of a cause to its effect; causality; influence; agency; operation; impulse: as, the action of wind upon a ship's sails.n. Manner of moving; kind of motion or physical performance: as, this horse has fine action; the action of a machine.n. In rhetoric, gesture or gesticulation; the deportment of the speaker, or the accommodation of his attitude, voice, gestures, and countenance to the subject, or to the thoughts and feelings expressed.n. In poetry and the drama, the connected series of events on which the interest of the piece depends; the main subject or story, as distinguished from an incidental action or episode. Unity of action is one of the dramatic unities.n. In physiology: Any one of the active processes going on in an organized body; some manifestation of vital activity; the performance of a function: as, the action of the stomach or the gastric juice on the food; a morbid action of the liver.n. A more or less complex muscular effort.n. In law: A proceeding instituted in court by one or more parties against another or others to enforce a right, or punish or redress a wrong: distinguished from judicial proceedings which are not controversial in form, as the probate of a will.n. Such a proceeding under the forms of the common law, as distinguished from a chancery suit and a criminal prosecution.n. The right of bringing an action: as, the law gives an action for every claim.n. In the fine arts: The appearance of animation, movement, or passion given to figures by their attitude, position, or expression, either singly or concurrently.n. The event or episode represented or illustrated by a work of art.n. A military fight; a minor engagement between armed bodies of men, whether on land or water: of less importance than a battle. See battle.n. In machinery: The mechanism of a breech-loading gun by which it is opened to receive the charge.n. That part of the mechanism of a pianoforte, an organ, or other similar instrument by which the action of the fingers upon the keys is transmitted to the strings, reeds, etc.n. A share in the capital stock of a company; in the plural, stocks, or shares of stock.n. In firearms, when the locks are bedded into the stock alone. E. H. Knight.To bring a legal action against.n. n. n. In mech., the sum of the average momenta of the elements of a moving system, each multiplied by the distance through which it moves.n. In dynamo-electric machines, wasteful internal circuits in the pole-pieces or cores; eddy, parasitic, or Foucault currents.