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

But this isn't a first act of kindness for Anderson. — Dominic Rech, CNN, "A plumber fixed the boiler of a 91-year-old terminally ill woman. He billed her $0," 17 Sep. 2019 Bloomberg Muddying the waters Continuing its rollback of Obama-era environmental policies, the White House last week repealed a 2015 clean water act, which curtailed the seepage of chemicals into U.S. water supplies. — Eamon Barrett, Fortune, "Is The Tech Sector Going On Climate Strike? — The Loop," 17 Sep. 2019 The No Filter Tour makes The Rolling Stones the first act to gross more than $400 million on two separate tours. — Eric Frankenberg, Billboard, "The Rolling Stones Wrap 3-Leg, 3-Year No Filter Tour With $415.6 Million," 12 Sep. 2019 The Bourbon & Beyond three-day music event returns to Louisville on Friday through Sunday with the promise of a unique mix of rock, roots, bluegrass and folk acts plus bourbon experts and culinary superstars. — Kirby Adams, The Courier-Journal, "Here's your complete guide to the 2019 Bourbon & Beyond music festival," 12 Sep. 2019 Maná Mexican rock icons Maná make history at the Forum this fall as the first act to play seven shows at the venue in a single year. — Andrea Domanick, Los Angeles Times, "The best concerts to see in L.A. this fall, from Lana Del Rey to Lizzo," 11 Sep. 2019 Muschietti is certainly a gifted visualist, lending poignancy to an engaging first act with dreamlike segues that pierce the metaphysical veil and tighten the cosmic tapestry that unites the Losers. — San Diego Union-Tribune, "Review: Overlong ‘It Chapter Two’ confronts scarier evils than Pennywise the clown," 5 Sep. 2019 One of Bolsonaro’s first official acts as president in early 2019 was to transfer the agency charged with supporting indigenous people, FUNAI, under the Ministry of Agriculture. — Time, "The Real Reason the Amazon Is On Fire," 26 Aug. 2019 Hip-hop has been around for more than 45 years, and Indianapolis rappers are still striving to be the city’s first act to break through to the mainstream. — David Lindquist, Indianapolis Star, "He's taking the stairs, not the elevator, but Indianapolis rapper Trajik just keeps rising," 22 Aug. 2019

Recent Examples on the Web: Verb

Those interested would be wise to act fast, because the property is sure to get scooped up quickly. — Brigit Katz, Smithsonian, "Live Like Lady Mary Crawley with a One-Night Stay at Downton Abbey," 17 Sep. 2019 Some of the writing called on characters to act not at all like themselves. — Julie Washington, cleveland.com, "Royal visit adds pomp to ‘Downton Abbey’ the movie: Review," 17 Sep. 2019 The plan is intended to act as a guide for land uses in Tomball—where residential, commercial and industrial properties could be placed. — Paul Wedding, Houston Chronicle, "Tomball City Council approves comprehensive plan," 16 Sep. 2019 The drop is largely due to the Mexican government’s efforts to stop migrants from heading north after Trump threatened tariffs earlier this year to force Mexico to act. — Astrid Galvan, The Denver Post, "450 miles of border wall by next year? In Arizona, it starts," 14 Sep. 2019 But if Mr Di Tella is right, then Argentina’s self-conscious attempt to act normal may have helped prevent it from becoming so. — The Economist, "Were Mauricio Macri’s mainstream policies doomed from the start?," 14 Sep. 2019 Glass perfume bottles act as prismatic objets, and a marble slab styled with gold bijoux is part catchall, part art. — Jessica Dailey, ELLE Decor, "How to Turn Your Bedroom Into a Coastal Italian Retreat," 10 Sep. 2019 Tiger's suicide acted as a mirror for the department. — AZCentral.com, "Police shootings in Arizona," 10 Sep. 2019 The Marvel series, being developed for the upcoming streaming service Disney+, has tapped Jonathan Igla to act as writer and executive producer. — Borys Kit, The Hollywood Reporter, "Marvel's 'Hawkeye' Series Finds Its Writer With 'Mad Men' Scribe (Exclusive)," 6 Sep. 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

acrylonitrile-butadiene-styrene

Statistics for act

Last Updated

15 Oct 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