act

noun \ ˈakt \

Updated on: 28 Nov 2017

Definition of act

1 a : 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

5 a : 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

See act defined for English-language learners

See act defined for kids

Examples of act in a Sentence

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.

Recent Examples of act from the Web

The first act is a quick half hour of merriment that includes Mimi and Rodolfo falling in love almost immediately, though their pas de deux is welcome by that point, and simply beautiful.

— lauren warnecke, chicagotribune.com, "Milwaukee Ballet's 'La Boheme' makes the passionate Paris story the star," 3 Nov. 2017
There has been an outpouring of concern for the victim of these acts from across the University and the country.

— Essence.com, "#JusticeForJazzy: University Of Hartford President Confirms Brianna Brochu Is No Longer Attending The School," 2 Nov. 2017
The incident is being investigated as an act of terror.

— glenn e. rice and judy l. thomas, kansascity, "NYC terror suspect ticketed in Platte County for bad brakes | The Kansas City Star," 1 Nov. 2017
What was most compelling about Una was that the film committed more thoughtfully to an act of audience destabilization.

— sophie gilbert, The Atlantic, "When Rape Is a Plot Twist," 31 Oct. 2017
Police believe Saipov was driving a rental truck that plowed down people on a Manhattan bike path Tuesday afternoon in what officials are describing as an act of terror.

— leada gore, AL.com, "Who is Sayfullo Saipov? 29-year old is suspect in deadly New York City truck attack," 31 Oct. 2017
Haley, succeeding where others failed, was lauded for her delicate act of political courage.

— david m. drucker, The Hive, "Trump, “Heritage,” and the G.O.P.’s White Identity Crisis," 27 Oct. 2017
The incident is being investigated as an act of criminal damaging, not as a hate crime, Blankenship said.

— sheila vilvens, Cincinnati.com, "Clermont County man: 'It does feel like a hate crime'," 27 Oct. 2017
Warner told Putesky of his vision for a rock band that would take the theatrics of acts like Kiss and Alice Cooper but add a darker, gruesome gothic twist.

— howard cohen, miamiherald, "Marilyn Manson co-founder, Scott Putesky, aka Daisy Berkowitz, dies at 49," 24 Oct. 2017

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.

Origin and Etymology of 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

NEW! Time Traveler

First Known Use: 14th century

See Words from the same year

act Synonyms

Synonyms

bit, number, routine, shtick (also schtick or shtik), turn

Related Words

signature

Near Antonyms

bluntness, candidness, candor, directness, forthrightness, frankness, openheartedness, outspokenness, plainspokenness, sincerity, straightforwardness; artlessness, genuineness, naïveté (also naivete or naiveté)

act

verb

Definition of act

intransitive verb

1 : to take action : move

think before acting

acted favorably on the recommendation

2 : to conduct oneself : behave

act like a fool

3 a : 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

1 a : 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

—

actability

play \ˌak-tə-ˈbi-lə-tē\ noun

—

actable

play \ˈak-tə-bəl\ adjective

See act defined for English-language learners

Examples of act in a Sentence

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 of act from the Web

These departments are allowed to act independently.

— marjie lundstrom, sacbee, "What are California taxpayers spending to settle sexual harassment claims? Good luck finding out," 3 Nov. 2017
Eventually the trainers brought in Tula, an older rescued otter, to act as a surrogate mother.

— marlene adelstein, Longreads, "When a Mother and Daughter Reverse Roles," 3 Nov. 2017
Sessions said in September there will be six-month delay in terminating the program to allow Congress time to act.

— janette vazquez, miamiherald, "Figuring out a path forward for 800,000 'dreamers' | Miami Herald," 2 Nov. 2017
The skin also acts as a barrier, preventing the delicate flesh of the fish from getting blasted with direct heat.

— alex delany, Bon Appetit, "How to Pan Sear Salmon Perfectly, Because You're Worth It," 30 Oct. 2017
The president’s allies are likely to act like this is a big nothingburger, and to dismiss Manafort as someone who was only briefly within Trump’s inner circle.

— alex shephard, New Republic, "Paul Manafort is the first domino to fall in Robert Mueller’s Russia probe.," 30 Oct. 2017
Patrick Phillips, the acting director of the Knight campus, thanked lawmakers for backing the project.

— andrew theen, OregonLive.com, "More than a building: UO reveals first look at Knight science campus plans," 27 Oct. 2017
But in the letter denying the permits, Rick Obernesser, acting regional director of the Park Service, wrote that the height exception should never have been approved and the agency was revoking the variance.

— perry stein, Washington Post, "Park Service denies permit for a 45-foot statue of a naked woman on the Mall," 26 Oct. 2017
But there is still time to act to prevent that from happening.

— gregory d. koblentz, Slate Magazine, "Smallpox Could Again Be a Serious Threat," 19 Oct. 2017

Origin and Etymology of act

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

NEW! Time Traveler

First Known Use: 1590

See Words from the same year

act Synonyms

Synonyms

do, impersonate, interpret, perform, play, portray

Related Words

depict, dramatize, render, represent; act out, enact, pantomime, playact, role-play, take on; overact, overplay, underplay; ape, clown, ham, imitate, masquerade, mime, mimic, pose (as); star (in); coact, costar

Near Antonyms

backfire; fizzle

act

abbreviation

Definition of act

1 active

2 actor

3 actual

Other Performing Arts Terms

diva, dramaturgy, loge, prestidigitation, proscenium, supernumerary, zany

ACT

abbreviation

Definition of ACT

1 Action for Children's Television

2 Association of Classroom Teachers

3 Australian Capital Territory

See ACT defined for English-language learners

Other Education Terms

baccalaureate, colloquium, corequisite, dissertation, monograph, pedant, practicum, survey course, thesis

ACT

trademark \ ˌā-ˌsē-ˈtē \

Definition of ACT

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

Other Education Terms

baccalaureate, colloquium, corequisite, dissertation, monograph, pedant, practicum, survey course, thesis

ACT Defined for English Language Learners

act

noun

Definition of act for English Language Learners

: something that is done
: a law made by a group of legislators
: one of the main divisions of a play or opera

act

verb

Definition of act for English Language Learners

: to do something : to take action
: to behave in a particular way
: to behave in a way that is not sincere or honest

ACT Defined for Kids

act

noun \ ˈakt \

Definition of act for Students

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

Definition of act for Students

acted; acting

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

Medical Dictionary

act

noun \ ˈakt \

medical Definition of act

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

1 : to perform an act : behave

2 : to produce an effect

wait for a medicine to act

act

abbreviation

medical Definition of act

active

Law Dictionary

act

noun

legal Definition of act

1 a : 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

2 a 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 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

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

—

actor

play \ˈak-tər\ noun

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act

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ACT

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Definition of act for English Language Learners

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Definition of act for English Language Learners

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act

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act

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Medical Dictionary

act

medical Definition of act

act

medical Definition of act

act

medical Definition of act

Law Dictionary

act

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act

legal Definition of act

actor

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