act

1 of 5

noun

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

act

2 of 5

verb

acted; acting; acts

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
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 noun
actable adjective

act

3 of 5

abbreviation (1)

1
active
2
actor
3
actual

ACT

4 of 5

abbreviation (2)

1
Action for Children's Television
2
Association of Classroom Teachers
3
Australian Capital Territory
used for a standardized achievement test to evaluate suitability for college admission
Phrases
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

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
The Kings were back in Edmonton for the third installment of their postseason trilogy Monday and the first act did not go well, with the Oilers scoring twice in the first 10 minutes on their way to a 7-4 win. Kevin Baxter, Los Angeles Times, 23 Apr. 2024 Other acts on this year’s lineup include Teddy Swims, Slowdive, Killer Mike, TV Girl, Charley Crockett, Men I Trust, Ben Howard, Amyl and the Sniffers, Kevin Abstract, Romy, Badbadnotgood, Strfkr, Corinne Bailey Rae, Snakehips, Allen Stone and more. Gil Kaufman, Billboard, 23 Apr. 2024 All three acts have gone on to other successes, but this tour brings together the songs and sounds that first brought them to fame. Jem Aswad, Variety, 23 Apr. 2024 The Supreme Court said Nixon couldn't be sued for official acts. USA TODAY, 23 Apr. 2024 Israel’s decision to attack Egypt in June 1967 was not only a preemptive strike but also an act of nightmarish panic. Tom Segev, Foreign Affairs, 23 Apr. 2024 The move could be seen as an act of desperation from Grayscale, the world’s largest crypto asset manager. Vinamrata Chaturvedi, Quartz, 22 Apr. 2024 Honestly, people engage in this act every single day. Heide Janssen, Orange County Register, 21 Apr. 2024 The album’s success validated the act — to an extent. Katie Bain, Billboard, 11 Apr. 2024
Verb
In March, the SAPD filed an appeal with the Texas attorney general, seeking to have the responsive records withheld under a laundry list of exemptions provided for by the state’s public records act. Max Blaisdell, WIRED, 24 Apr. 2024 Critics said Rittenhouse had no right to fire his weapon and was illegally acting as a vigilante militia. USA TODAY, 24 Apr. 2024 The regulator has reminded broadcasters that its Broadcasting Code prohibits candidates in U.K. elections from acting as news presenters, interviewers or presenters of any type of program during the election period. Naman Ramachandran, Variety, 24 Apr. 2024 Some of the shrimp is finely chipped into a paste with onion and garlic to act as a binder when mixed with big chunks of shrimp, offering a range of bouncy, fluffy and tender textures. Paola Briseño-Gonzalez, Los Angeles Times, 24 Apr. 2024 Three decades later, The Who’s Tommy is back in its first major Broadway revival — a searing production with a cast of standout vocal and acting talent led by 24-year old Ali Louis Bourzgui as Tommy. Rebecca Milzoff, Billboard, 24 Apr. 2024 The first effectively acts as a second pair of eyes for the driver, providing things like automatic emergency braking and lane departure warnings. IEEE Spectrum, 24 Apr. 2024 That’s why Wedbush’s Ives said Musk needed to show up with his big boy pants on this time and act like an adult after his recent spate of poor performances that only unnerved investors. Christiaan Hetzner, Fortune, 24 Apr. 2024 There are classes on acting from Steve Martin and Helen Mirren, on photography from Annie Leibovitz, on music from Ringo Starr, on science and technology from Neil deGrasse Tyson and James Cameron, to name a few. Claire Peltier, ABC News, 12 Apr. 2024

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'act.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

Etymology

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

First Known Use

Noun

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

Verb

1590, in the meaning defined at intransitive sense 2

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

Dictionary Entries Near act

Cite this Entry

“Act.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/act. Accessed 27 Apr. 2024.

Kids Definition

act

1 of 2 noun
1
: something that is done
an act of kindness
2
: the doing of something
caught in the act
3
: a law made by a governing body
an act of Congress
4
a
: one of the main divisions of a play or opera
b
: one of the parts of a variety show or circus
5
: a display of behavior that is not sincere
just putting on an act

act

2 of 2 verb
1
: to perform by action especially on the stage
2
: to play the part of
act the man of the world
3
a
: to behave in a manner suitable to
act your age
b
: to conduct oneself
act like a fool
4
: to take action : move
think before you act
5
a
: to perform a function : serve
act as mayor
b
: to produce an effect : work
wait for a medicine to act
Etymology

Noun

Middle English act "act, deed," from Latin actus "action of doing" and from Latin actum "something done," both from agere "to drive, do" — related to agent

Medical Definition

act

1 of 3 noun
1
: a motor performance leading to a definite result
2
: a dealing with objects (as by moving, perceiving, or desiring them)

act

2 of 3 intransitive verb
1
: to perform an act : behave
2
: to produce an effect
wait for a medicine to act

act

3 of 3 abbreviation
active

Legal Definition

act

1 of 2 noun
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 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

act

2 of 2 intransitive verb
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
actor noun

More from Merriam-Webster on act

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