act

noun

\ ˈakt

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

act

verb

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

c : impersonate

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

act

abbreviation (1)

Definition of act (Entry 3 of 5)

1 active

2 actor

3 actual

ACT

abbreviation (2)

Definition of ACT (Entry 4 of 5)

1 Action for Children's Television

2 Association of Classroom Teachers

3 Australian Capital Territory

ACT

trademark

\ ˌā-ˌsē-ˈtē\

Definition of ACT (Entry 5 of 5)

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

Other Words from act Synonyms More Example Sentences Learn More about act

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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.

Recent Examples on the Web: Noun

Refusing to use someone's correct pronouns and name is an act of transphobia. — Megan Lasher, Seventeen, "What Does 'Cisgender' Mean?," 13 Mar. 2019 These devotions are an act of penitence to raise awareness of Jesus’s self-sacrifice and love, says Morrill. — Arricca Elin Sansone, Country Living, "What Is Holy Saturday, the Day Before Easter, and Why Do We Celebrate It?," 1 Mar. 2019 No sale: Shepard aimed for high significance but settled in the second act for noisy obviousness. — Terry Teachout, WSJ, "‘True West’ Review: Family Feud via Tinseltown," 24 Jan. 2019 In one act, a mercurial and generous Jeff Bezos would bestow a city with riches beyond their imagination: an all-American tech company, tens of thousands of jobs, and $5 billion in investments. — Jacob Kastrenakes, The Verge, "The Verge 2018 tech report card: Amazon," 27 Dec. 2018 He's set up an elaborate camera system to capture Santa Claus in the act of leaving presents. — Jennifer Ouellette, Ars Technica, "Dial Code: Santa Claus is our new favorite holiday cult classic," 24 Dec. 2018 Changing the direction of a city is, naturally, a balancing act. — Patrick Sisson, Curbed, "Here’s what a plan to tackle climate change, density, and affordability looks like," 27 Nov. 2018 Claire and Kelsey’s personal lives are entangled this season based on a mutual connection to Tom Yates, Claire’s former lover who last season engaged in an impromptu act of intimacy with Kelsey in the White House press room. — Lonnie Firestone, Glamour, "House of Cards' Final Season Is About Women Gaining Power—at the Expense of Other Women," 10 Nov. 2018 Princess Beatrice of York also broke with royal protocol, but this was for the sweetest reason: in an act of support for her mother, Sarah, Duchess of York, who has been on ice with the Royal Family for years. — Amanda Mitchell, Marie Claire, "How Princess Eugenie's Wedding Broke Royal Protocol," 13 Oct. 2018

Recent Examples on the Web: Verb

The seeds in apples contain cyanide, which is toxic, and the core can act as a choking hazard for dogs of all size. — Jackie Frere, Woman's Day, "Can Dogs Eat Apples? A Veterinarian Weighs In," 2 Apr. 2019 Disney darling Dove Cameron has been acting for 7 years, playing everything from a villainess to Cher Horowitz. — Carolyn Twersky, Seventeen, "Dove Cameron's Net Worth is Hefty Thanks to All of Her Work for Disney," 27 Mar. 2019 Aqua octagonal tiles create a soothing tone in the entryway, pistachio velvet sofas add warmth to the living room and a merlot backsplash in the kitchen acts as a pop of interest. — Vanessa Lawrence, ELLE Decor, "Reath Design Crafts a Bright, Elegant Home for a Young Family," 22 Mar. 2019 There are two identical systems on Earth, somewhere within HP’s Engineering Department, acting as control groups for the orbiting systems. — Joe Pappalardo, Popular Mechanics, "The Saga of a Stranded Space Station Supercomputer," 18 Mar. 2019 Panicked at the possibility of the Hanover line losing the throne now that there was no direct heir, George IV, acting as regent for his father, and Parliament offered George III's sons a monetary incentive to produce a legitimate heir. — Lauren Hubbard, Town & Country, "Who Was Queen Victoria's Uncle, King Leopold I of Belgium?," 18 Feb. 2019 Zipf’s law is a reflection of the careful balancing act a language needs between variety and simplicity. — Brian Resnick, Vox, "What humpback whales can teach us about alien languages," 6 Dec. 2018 Veterans’ Affairs acting director Linda Chapa LaVia said in a statement. — John O'connor, The Seattle Times, "Audit: Slow Legionnaires’ response at Illinois veterans home," 25 Mar. 2019 Your pup acts crazy when there's not enough playtime. — Alexandra Gekas, Woman's Day, "9 Things Your Dog Is Trying to Tell You, According to Experts," 25 Feb. 2019

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.

History and Etymology for act

Noun

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

Verb

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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Dictionary Entries near act

Statistics for act

Last Updated

16 Apr 2019

Look-up Popularity

Time Traveler for act

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

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More Definitions for act

act

noun

English Language Learners Definition of act

(Entry 1 of 2)

: something that is done

: a law made by a group of legislators

: one of the main divisions of a play or opera

act

verb

English Language Learners Definition of act (Entry 2 of 2)

: to do something : to take action

: to behave in a particular way

: to behave in a way that is not sincere or honest

See the full definition for act in the English Language Learners Dictionary

act

noun

\ ˈakt

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.

act

verb

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

act

noun

\ ˈakt

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)

act

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

act

abbreviation

Medical Definition of act (Entry 3 of 3)

active

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act

noun

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 act — U.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

act

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 President — U.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