\ ˈakt How to pronounce act (audio) \

Essential Meaning of act

1 : something that is done His first official act [=action] as President was to sign the bill. We were grateful for her many acts of kindness. See More Examplesan act of bravery = a brave act criminal/illegal/unlawful/wrongful actsHide
2 : a law made by a group of legislators The program was created by (an) act of Congress/Parliament. legislative acts the Civil Rights Act of 1964
3 : one of the main divisions of a play or opera Please read act II, scene 1 of Shakespeare's Romeo and Juliet. In the first/opening act, two characters are talking in a restaurant. a play in three acts = a three-act play

Full Definition of act

 (Entry 1 of 5)

1a : the doing of a thing : deed an act of courage
b law : something done voluntarily
2 : the process of doing something : action caught in the act
3 : the formal product of a legislative body : statute an act of Congress also : a decision or determination of a sovereign, a legislative council, or a court of justice
4 : one of the principal divisions of a theatrical work (such as a play or opera) a play in three acts
5a : one of successive parts or performances (as in a variety show or circus) a magic act
b : the performer or performers in such an act a two-person comedy act
c : a performance or presentation identified with a particular individual or group They took their act on the road.
d : the sum of a person's actions or effects that serve to create an impression or set an example a hard act to follow
6 : a display of affected behavior : pretense put on an act that deceived nobody His friendly concern was just an act.
7 often capitalized : a formal record of something done or transacted
8 : a state of real existence rather than possibility
into the act or in on the act
: into an undertaking or situation as an active participant saw the success they were having and wanted to get in on the act


acted; acting; acts

Definition of act (Entry 2 of 5)

intransitive verb

1 : to take action : move think before acting acted favorably on the recommendation
2 : to conduct oneself : behave act like a fool
3a : to perform on the stage began acting at the age of eight
b : to behave as if performing on the stage : pretend seemed angry but was just acting
4 : to perform a specified function : serve trees acting as a windbreak
5 : to produce an effect : work wait for a medicine to act
6 : to give a decision or award adjourned without acting on the bill
7 of a play : to be capable of being performed a play that acts well

transitive verb

1a : to represent or perform by action especially on the stage will act the part of Romeo in tonight's play
b : feign, simulate act indifference
2 : to play the part of as if in a play act the man of the world
3 : to behave in a manner suitable to Act your age.
4 obsolete : actuate, animate

Definition of act (Entry 3 of 5)

1 active
2 actor
3 actual

Definition of ACT (Entry 4 of 5)

1 Action for Children's Television
2 Association of Classroom Teachers
3 Australian Capital Territory


\ ˌā-ˌsē-ˈtē How to pronounce ACT (audio) \

Definition of ACT (Entry 5 of 5)

used for a standardized achievement test to evaluate suitability for college admission

Other Words from act


actability \ ˌak-​tə-​ˈbi-​lə-​tē How to pronounce ACT (audio) \ noun
actable \ ˈak-​tə-​bəl How to pronounce ACT (audio) \ adjective

Synonyms for act

Synonyms: Noun

Synonyms: Verb

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Examples of act in a Sentence

Noun We were grateful for her many acts of kindness. the Civil Rights Act of 1964 Please read act II, scene 1 of Shakespeare's Romeo and Juliet. In the first act, two characters are talking in a restaurant. Verb He knew he had to act quickly. The government was slow to act. She acted on behalf of her father, who was not at the meeting. I believe that the killer acted alone. She had acted in self-defense when she killed her attacker. We were acting in the best interests of our children. We must act soon to end this crisis. She learned at an early age how to act properly in social situations. People are always telling me how I should act and what I should say. I noticed that the dog was acting funny this morning.
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Recent Examples on the Web: Noun Making this franchise a family affair isn’t the worst act of nepotism this industry has ever seen. Roxana Hadadi, Los Angeles Times, 18 Nov. 2021 This is still every bit the savvy act of demographic outreach the old records were. Craig Jenkins, Vulture, 17 Nov. 2021 Although many Americans consider courtship to be primarily an act between individuals, dating someone is a process of gradually fusing with their habits, their values, their community. Ginny Hogan, The Atlantic, 15 Nov. 2021 Triggering Article 16 in and of itself is not an unlawful act. Laura Smith-spark, CNN, 13 Nov. 2021 The instant relief and the reenergizing effect of a few minutes away from the screen — the time to brew some coffee or to just step out of the room to get some air — is such a simple but effective act. Johnny Warström, Forbes, 12 Nov. 2021 Balancing incremental progress with wins and losses is not an easy juggling act. oregonlive, 11 Nov. 2021 Pool and his attorneys said this incident was not the first racist act Campo did while on duty. Kaylee Remington, cleveland, 11 Nov. 2021 What Nichols describes is a brave and selfless act, and something U.S. Army veteran Colin Wayne can relate to. Matt Wake |, al, 11 Nov. 2021 Recent Examples on the Web: Verb Opioids act on parts of the brain and nervous system that regulate pain, says NIDA. Sarah Fielding,, 19 Nov. 2021 Lawmakers have, meanwhile, refused to act so far on a series of gun reforms proposed by Gov. Mike DeWine after a 2019 mass shooting in Dayton. Jeremy Pelzer, cleveland, 17 Nov. 2021 The pressure to act on climate change has grown in the past few years because fires, floods, and heat waves have grown worse. Robinson Meyer, The Atlantic, 17 Nov. 2021 To portray a future where the world has failed to act on global warming, The [uncertain] Four Seasons aimed to place pressure on world leaders at COP26 where a live performance was held in Glasgow. Dr Geraint Evans, Forbes, 15 Nov. 2021 The 400-member New Hampshire House will convene on Jan. 5 to act on bills vetoed by Governor Chris Sununu as well as bills that were retained for further work., 13 Nov. 2021 Bernadine Dittmar said while imploring the commission to act on behalf of future generations of Texas hunters and landowners, including her grandchildren. Matt Wyatt, San Antonio Express-News, 10 Nov. 2021 While there are no state regulations to act on odors, Beranek said there is a state law that gives IDEM the duty and obligation to protect general welfare from all air contaminants. Sarah Bowman, The Indianapolis Star, 9 Nov. 2021 The list included people either directly affiliated with fossil fuel companies, including Shell, Gazprom and BP, as well as those attending as members of delegations and groups that act on behalf of the fossil fuel industry. Angela Dewan, CNN, 8 Nov. 2021

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'act.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of act


14th century, in the meaning defined at sense 1a


1590, in the meaning defined at intransitive sense 2

History and Etymology for act


Middle English acte, borrowed from Anglo-French & Latin; Anglo-French acte, act, borrowed partly from Latin āctus "driving of cattle, track for cattle, movement, activity, performance, part of a play" (action noun from agere "to drive (cattle), cause to move, do"), partly from Latin āctum (usually in plural) "thing done, public transaction, record," from neuter of āctus, past participle of agere — more at agent


Middle English acten "to act upon, adjudicate," in part derivative of act act entry 1, in part borrowed from Latin āctus, past participle of agere

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The first known use of act was in the 14th century

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Last Updated

22 Nov 2021

Cite this Entry

“Act.” Dictionary, Merriam-Webster, Accessed 30 Nov. 2021.

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More Definitions for act


\ ˈakt How to pronounce act (audio) \

Kids Definition of act

 (Entry 1 of 2)

1 : something that is done : deed an act of bravery
2 : a law made by a governing body
3 : a main division of a play
4 : one of the performances in a show a juggling act
5 : an insincere way of behaving Her crying was just an act.


acted; acting

Kids Definition of act (Entry 2 of 2)

1 : to do something : move It's important to act quickly in an emergency.
2 : to behave oneself in a certain way He's been acting strangely.
3 : to perform as a character in a play Both stars agreed to act in the movie.
4 : to perform a certain function She'll act as our guide.
5 : to have a result : make something happen : work The medicine acts on the heart.
act up
: to behave badly


\ ˈakt How to pronounce act (audio) \

Medical Definition of act

 (Entry 1 of 3)

1 : a motor performance leading to a definite result
2 : a dealing with objects (as by moving, perceiving, or desiring them)


intransitive verb

Medical Definition of act (Entry 2 of 3)

1 : to perform an act : behave
2 : to produce an effect wait for a medicine to act



Medical Definition of act (Entry 3 of 3)




Legal Definition of act

 (Entry 1 of 2)

1a : something done by a person in accordance with his or her free will a tortious act — see also actus reus
b : the failure to do something that one has a legal duty to do

called also negative act

2a often capitalized : the formal product of a legislative body : the formally declared will of a legislature the final requirement of which is usually the signature of the proper executive officer : statute an act of Congress in furtherance of the purposes…of that actU.S. Code
b : a decision or determination of a sovereign, a legislative council, or a court of justice — compare bill sense 1
3 often capitalized : a formal record of something done or transacted given as my free act and deed


intransitive verb

Legal Definition of act (Entry 2 of 2)

1 : to carry into effect a determination of the will : take action
2 : to discharge the duties of a specified office or post : perform a specified function used with a prepositional phrase declaring what officer shall then act as PresidentU.S. Constitution art. II
3 : to give a decision or award (as by vote of a deliberative body or by judicial decree) often used with on adjourned with several important matters still not acted on

Other Words from act

actor \ ˈak-​tər How to pronounce act (audio) \ noun

More from Merriam-Webster on act

Nglish: Translation of act for Spanish Speakers

Britannica English: Translation of act for Arabic Speakers


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