• –noun1.the process or state of acting or of being active: Themachine is not in action now.2.something done or performed; act; act that one consciously wills and that may becharacterized by physical or mental activity: a crisis thatdemands action instead of debate; hoping for constructiveaction by the landlord.4.actions, habitual or usual acts; conduct: He is responsiblefor his actions.5.energetic activity: a man of exertion of power or force: the action of wind upon aship's sails.7.effect or influence: the action of morphine.8.Physiology . a change in organs, tissues, or cells leading toperformance of a function, as in muscular contraction.9.way or manner of moving: the action of a machine or of ahorse.10.the mechanism by which something is operated, as that of agun or a piano.11.a military encounter or engagement; battle, skirmish, or thelike.12.actual engagement in fighting an enemy; military or navalcombat: He saw action in Vietnam.13.Literature . the main subject or story, as distinguished froman incidental episode.14.Theater event or series of events that form part of adramatic plot: the action of a of the three unities. Compare unity ( def. 8 ) .15.the gestures or deportment of an actor or speaker.16.Fine Arts . the appearance of animation, movement, oremotion given to figures by their attitude, position, orexpression.17.Law .a.a proceeding instituted by one party against another.b.the right of bringing it.18.Slang .a.interesting or exciting activity, often of an illicit nature:He gave us some tips on where the action was.b.gambling or the excitement of gambling: The casinousually offers plenty of bet in gambling, esp. illegally.19.Ecclesiastical .a.a religious ceremony, esp. a Eucharistic service.b.the canon of the Mass.c.those parts of a service of worship in which thecongregation participates.–adjective20.characterized by brisk or dynamic action: an action car; anaction melodrama.— action,a.performing or taking part in a characteristic act: Theschool baseball team is in action tonight.b.working; functioning: His rescuing the child was braveryin action.22.out of action, removed from action, as by sudden disability:The star halfback is out of action with a bad knee.23.piece of the action, Informal . a share of the proceeds orprofits: Cut me in for a piece of the action.24.take action, start doing something: As soon as we get hisdecision, we'll take start a legal procedure. Use action in a SentenceOrigin:

1300–50; < L āctiōn- (s. of āctiō), equiv. to āct ( us ) (ptp.; seeact) + -iōn- -ion; r. ME accioun < AF < L —Related formsac·tion·less, adjectivenon·ac·tion, nounpre·ac·tion, nounpro·ac·tion, adjective —Synonyms 1. movement, operation. 2. Action, act, deed mean somethingdone. Action applies esp. to the doing, act to the result of thedoing. An action usually lasts through some time and consists ofmore than one act: to take action on a petition. An act is single:an act of kindness. Deed emphasizes the finished or completedquality of an act; it may imply an act of some note, good or bad:an irrevocable deed; a deed of daring. 4. behavior. 12. brush,encounter, fight, skirmish. See battle. 15. plot.

—Antonyms 1. rest, inactivity.