1. (n.) That which is done or doing; the exercise of power, or the effect, of which power exerted is the cause; a performance; a deed.

2. (n.) The result of public deliberation; the decision or determination of a legislative body, council, court of justice, etc.; a decree, edit, law, judgment, resolve, award; as, an act of Parliament, or of Congress.

3. (n.) A formal solemn writing, expressing that something has been done.

4. (n.) A performance of part of a play; one of the principal divisions of a play or dramatic work in which a certain definite part of the action is completed.

5. (n.) A thesis maintained in public, in some English universities, by a candidate for a degree, or to show the proficiency of a student.

6. (n.) A state of reality or real existence as opposed to a possibility or possible existence.

7. (n.) Process of doing; action. In act, in the very doing; on the point of (doing).

8. (v. t.) To move to action; to actuate; to animate.

9. (v. t.) To perform; to execute; to do.

10. (v. t.) To perform, as an actor; to represent dramatically on the stage.

11. (v. t.) To assume the office or character of; to play; to personate; as, to act the hero.

12. (v. t.) To feign or counterfeit; to simulate.

13. (v. i.) To exert power; to produce an effect; as, the stomach acts upon food.

14. (v. i.) To perform actions; to fulfill functions; to put forth energy; to move, as opposed to remaining at rest; to carry into effect a determination of the will.

15. (v. i.) To behave or conduct, as in morals, private duties, or public offices; to bear or deport one's self; as, we know not why he has acted so.

16. (v. i.) To perform on the stage; to represent a character.

accomplish accomplished fact accomplishment achieve achievement acquit act act a part act as act as foil act out acta acting action actions activism activity acts address adventure affect affectation afterpiece air ape appear assume barnstorm be effective be in action be productive bear bearing behave behavior behavior pattern behavioral norm behavioral science bill bit blow bluff bring about bring into being bring to fruition bylaw canon carriage carry cause characterize chaser come out comport comportment concurrent resolution conduct constitution copy counterfeit coup course cover up culture pattern curtain curtain call curtain raiser custom dealings decree deed demean demeanor deport deportment dictate dictation discourse dissemble dissimulate divertimento divertissement do doing doings edict effectuate effort emote emotionalize employment enact enaction enactment endeavor engineer enterprise epilogue execute exercise exode exodus exploit expository scene fait accompli fake feat feign finale folkway form formality formula formulary four-flush function functioning gammon gest gestures get top billing go go on goings-on guise hand handiwork have effect have free play have play hoke act impersonate industrialize institution interlude intermezzo intermission introduction job joint resolution jus law lawmaking legislation legislature let on let on like lex maintien make make a pretense make as if make believe make like maneuver manner manners masquerade masquerade as mass-produce measure method methodology methods mien militate mime mimic misbehave modus vivendi motion motions move movements moves number observable behavior occupation officiate operate operation operations ordinance ordonnance overproduce overt act pantomime pass for passage passing patter pattern percolate perform performance perk personate play play a part play possum play the lead playact poise port portray pose pose as posture practice praxis prescript prescription presence pretend pretend to be procedure proceed proceeding process produce production profess prologue put on quit react realize register regulation represent res gestae resolution routine rubric rule ruling run scene serve sham shtick simulate sketch skit social science song and dance stand-up comedy act standing order star statute steal the show step stooge striptease