the process of doing: caught in the act.
a formal decision, law, or the like, by a legislature, ruler, court, or other authority; decree or edict; statute; judgment, resolve, or award: an act of Congress.
an instrument or document stating something done or transacted.
one of the main divisions of a play or opera: the second act of Hamlet.
a short performance by one or more entertainers, usually part of a variety show or radio or television program.
the personnel of such a group: The act broke up after 30 years.
Philosophy. (in scholasticism)
activity in process; operation.
the principle or power of operation.
form as determining essence.
a state of realization, as opposed to potentiality.
to do something; exert energy or force; be employed or operative: He acted promptly in the emergency.
to reach, make, or issue a decision on some matter: I am required to act before noon tomorrow.
to operate or function in a particular way; perform specific duties or functions: to act as manager.
to produce an effect; perform a function: The medicine failed to act.
to behave or conduct oneself in a particular fashion: to act well under all conditions.
to pretend; feign: Act interested even if you're bored.
to perform as an actor: He acted in three plays by Molière.
to be capable of being performed: His plays don't act well.
to serve or substitute (usually followed by for): In my absence the assistant manager will act for me.
to represent (a fictitious or historical character) with one's person: to act Macbeth.
to behave as: He acted the fool.
Obsolete. to actuate.
act on / upon
to demonstrate or illustrate by pantomime or by words and gestures: The party guests acted out stories for one another.
Psychology. to give overt expression to (repressed emotions or impulses) without insightful understanding: The patients acted out early traumas by getting angry with the analyst.
to fail to function properly; malfunction: The vacuum cleaner is acting up again.
to behave willfully: The children always act up in school the day before a holiday.
to become painful or troublesome, especially after a period of improvement or remission: My arthritis is acting up again this morning.
get / have one's act together Informal. to organize one's time, job, resources, etc., so as to function efficiently: The new administration is still getting its act together.
Idioms about act
act funny, to display eccentric or suspicious behavior.
act one's age, to behave in a manner appropriate to one's maturity: We children enjoyed our uncle because he didn't always act his age.
clean up one's act, Informal. to begin adhering to more acceptable practices, rules of behavior, etc.: The factory must clean up its act and treat its employees better.
- mis·act, verb (used without object)
- postact, noun
- pre·act, verb (used with object)
- un·act·ed, adjective
- well-acted, adjective
Other definitions for ACT (2 of 3)
Trademark. a standardized college admissions test developed by ACT, Inc., measuring English, mathematics, reading, and science skills: originally an abbreviation of American College Testing/American College Test.: Compare SAT.
Association of Classroom Teachers.
Australian Capital Territory.
Other definitions for act. (3 of 3)
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
How to use act in a sentence
The simple act of wearing a covering over one’s mouth and nose has become particularly divisive as some question the changing recommendations issued by top health organizations.Inconclusive results, missing data: Experts push back on a study questioning the efficacy of masks | Meryl Kornfield | November 20, 2020 | Washington Post
In so doing, he dismisses as “very unlikely” the suggestion that Nero ordered the burning of his capital — an act that would have been both illogical and difficult.
The records act makes no exception for cases in which searching for a public record “would require the state to work hard,” the analysis found.Junior Staffer Says Top Alaska Official Told Her to Keep Allegations of Misconduct Secret | by Kyle Hopkins, Anchorage Daily News | November 18, 2020 | ProPublica
Proving that something is impossible is a powerful act of mathematics.Some Math Problems Seem Impossible. That Can Be a Good Thing. | Patrick Honner | November 18, 2020 | Quanta Magazine
Outside contributor Daniel Duane traveled to Southern California to talk to Corliss about his latest high-wire act.
Servis, a general contractor, was baffled by how introverted Stone acted.
When they thought about Lewis, what struck the players most was that he never acted like a do-gooder.
LAPD police chief Charlie Beck concluded Corrales and Diego had acted reasonably.Worse Than Eric Garner: Cops Who Got Away With Killing Autistic Men and Little Girls | Emily Shire | December 4, 2014 | THE DAILY BEAST
But Stephen Kotkin's new biography reveals a learned despot who acted cunningly to take advantage of the times.
I dressed as a girl, lived as a girl, acted as a girl, and that was that.Exclusive: Michael Phelps’s Intersex Self-Proclaimed Girlfriend, Taylor Lianne Chandler, Tells All | Aurora Snow | November 26, 2014 | THE DAILY BEAST
Whereas Lessard had acted the martinet with MacRae, he took another tack and became the very essence of affability toward me.Raw Gold | Bertrand W. Sinclair
He acted dejected and dispirited, and if he could have talked would have asked the meaning of it all.The Courier of the Ozarks | Byron A. Dunn
Mr. Wainwright acted as secretary and I kept the minute book and papers relating to the business of the committee.Fifty Years of Railway Life in England, Scotland and Ireland | Joseph Tatlow
Thereupon the unhappy woman acted; the long suppressed outburst came at last.Dope | Sax Rohmer
This was a somewhat singular mode of stimulating, but he deemed it the wisest course, and acted on it.Hunting the Lions | R.M. Ballantyne
British Dictionary definitions for act (1 of 3)
something done or performed; a deed
the performance of some physical or mental process; action
(capital when part of a name) the formally codified result of deliberation by a legislative body; a law, edict, decree, statute, etc
(often plural) a formal written record of transactions, proceedings, etc, as of a society, committee, or legislative body
a major division of a dramatic work
a short performance of skill, a comic sketch, dance, etc, esp one that is part of a programme of light entertainment
those giving such a performance
an assumed attitude or pose, esp one intended to impress
philosophy an occurrence effected by the volition of a human agent, usually opposed at least as regards its explanation to one which is causally determined: Compare event (def. 4)
(intr) to do something; carry out an action
(intr) to function in a specified way; operate; react: his mind acted quickly
to perform (a part or role) in a play, etc
(tr) to present (a play, etc) on stage
(intr; usually foll by for or as) to be a substitute (for); function in place (of)
(intr foll by as) to serve the function or purpose (of): the glass acted as protection
(intr) to conduct oneself or behave (as if one were): she usually acts like a lady
(intr) to behave in an unnatural or affected way
(copula) to pose as; play the part of: to act the fool
(copula) to behave in a manner appropriate to (esp in the phrase act one's age)
(copula) not standard to seem or pretend to be: to act tired
clean up one's act to start to behave in a responsible manner
get in on the act informal to become involved in a profitable undertaking or advantageous situation in order to share in the benefits
get one's act together informal to become organized or prepared
- actable, adjective
- actability, noun
British Dictionary definitions for ACT (2 of 3)
Australian Capital Territory
(formerly in Britain) advance corporation tax
British Dictionary definitions for ACT (3 of 3)
(in New Zealand) Association of Consumers and Taxpayers: a small political party of the right
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Other Idioms and Phrases with act
In addition to the idioms beginning with act
- act of faith
- act of God
- act on
- act one's age
- act out
- act up
- act upon
- catch in the act
- clean up (one's act)
- do a disappearing act
- get in the act
- get one's act together
- hard (tough) act to follow
- high-wire act
- in the act of
- put on an act
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.