act up

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1. The process of doing or performing something: the act of thinking.
a. Something done or performed; a deed: a charitable act.
b. Law Something done that has legal significance: a criminal act.
3. A statute or other law formally adopted by a legislative body: an act of Congress.
4. A formal written record of proceedings or transactions.
5. One of the major divisions of a play, opera, or film.
a. A performance or entertainment usually forming part of a longer presentation: a juggling act; a magic act.
b. The actor or actors presenting such a performance: joined the act in Phoenix.
7. A manifestation of intentional or unintentional insincerity; a pose: put on an act.
v. act·ed, act·ing, acts
1. To play the part of; assume the dramatic role of: She plans to act Ophelia in summer stock.
2. To perform (a role) on the stage: act the part of the villain.
a. To behave like or pose as; impersonate: Don't act the fool.
b. To behave in a manner suitable for: Act your age.
1. To behave or comport oneself: She acts like a born leader.
2. To perform in a dramatic role or roles.
3. To be suitable for theatrical performance: This scene acts well.
4. To behave affectedly or unnaturally; pretend.
5. To appear or seem to be: The dog acted ferocious.
6. To carry out an action: We acted immediately. The governor has not yet acted on the bill.
7. To operate or function in a specific way: His mind acts quickly.
8. To serve or function as a substitute for another: A coin can act as a screwdriver.
9. To produce an effect: waited five minutes for the anesthetic to act.
Phrasal Verbs:
act out
1. To perform in or as if in a play; represent dramatically: act out a story.
2. To realize in action: wanted to act out his theory.
3. To engage in socially inappropriate or impulsive behavior as a manifestation of psychological or emotional pain or turmoil.
act up
1. To misbehave.
2. To malfunction.
3. Informal To become active or troublesome after a period of quiescence: My left knee acts up in damp weather. Her arthritis is acting up again.
be in on the act
To be included in an activity.
clean up (one's) act Slang
To improve one's behavior or performance.
get into the act
To insert oneself into an ongoing activity, project, or situation.
get (one's) act together Slang
To get organized.

[Middle English, from Old French acte, from Latin āctus, a doing, and āctum, a thing done, both from past participle of agere, to drive, do; see ag- in Indo-European roots.]

ac′ta·bil′i·ty n.
act′a·ble adj.
Usage Note: Act and action both mean "a deed" and "the process of doing." However, other senses of act, such as "a decision made by a legislative body" and of action, such as "habitual or vigorous activity" show that act tends to refer to a deed while action tends to refer to the process of doing. Thus, people engage in sex acts but not sex actions. By the same token, one may want a piece of the action, but not a piece of the act. The demands of meaning or idiom often require one word or the other. In some cases, either can be used: my act (or action) was premature.


A trademark for a standardized college entrance examination.


Australian Capital Territory
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

act up

(intr, adverb) informal to behave in a troublesome way: the engine began to act up when we were miles from anywhere.
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014
ThesaurusAntonymsRelated WordsSynonymsLegend:
Verb1.act up - misbehave badlyact up - misbehave badly; act in a silly or improper way; "The children acted up when they were not bored"
misbehave, misconduct, misdemean - behave badly; "The children misbehaved all morning"
2.act up - make itself felt as a recurring painact up - make itself felt as a recurring pain; "My arthritis is acting up again"
hurt, smart, ache - be the source of pain
Based on WordNet 3.0, Farlex clipart collection. © 2003-2012 Princeton University, Farlex Inc.


1. The process of doing:
2. Something done:
3. The formal product of a legislative or judicial body:
4. A short theatrical piece within a larger production:
5. A display of insincere behavior:
1. To conduct oneself in a specified way:
2. To behave affectedly or insincerely or take on a false or misleading appearance of:
3. To react in a specified way:
4. To perform the duties of another:
5. To play the part of:
6. To produce on the stage.Also used with out:
phrasal verb
act up
1. To behave in a rowdy, improper, or unruly fashion:
Informal: cut up, horse around.
2. To work improperly due to mechanical difficulties:
The American Heritage® Roget's Thesaurus. Copyright © 2013, 2014 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

w>act up

vi (inf)jdm Ärger machen; (person also)Theater machen (inf); (to attract attention) → sich aufspielen; (machine)verrücktspielen (inf); my back is acting upmein Rücken macht mir Ärger
Collins German Dictionary – Complete and Unabridged 7th Edition 2005. © William Collins Sons & Co. Ltd. 1980 © HarperCollins Publishers 1991, 1997, 1999, 2004, 2005, 2007
References in periodicals archive ?
My reading maps a broader Right To Try discourse against the register of regulatory language then considers that reading in the light of ACT UP's activist critique of the FDA.
Along-standing controversy within act up centered on the effectiveness of some of the organization's tactics.
Ultimately, center stage goes to the small group of activists who created the Treatment Action Group (tag), an offshoot of act up, and who managed to work their way inside the pharmaceutical industry.
"So many of us in Gays Against Guns are ACT UP babies," Grauwiler told me, "and we saw the effect of political theater and direct action firsthand.
However, since September 11, I have felt the need for some evidence and encouragement, and I found it in From ACT UP to the WTO: Urban Protest and Community Building in the Era of Globalization, a collection of compulsively readable analyses, first person stories, and interviews of forty-one activists brilliantly edited and introduced by Benjamin Shepard and Ronald Hayduk.
When ACT UP was first formed in New York in the late 1980s, its weekly meetings regularly attracted up to a thousand members--largely drawn from white, middle-class gay and lesbian communities.
By June of 1989, Signorile had once again burst onto the scene, this time as a columnist for Outweek, the gay and lesbian news magazine of the ACT UP generation.
By highlighting the ways in which these dramatists accomplished as much and helped revolutionize Western theater, we will lay the groundwork for linking such artistic practices to the street theater of ACT UP to unveil a theatrical genealogy wherein audiences are constantly asked to bear witness to the morals and ethics of the issues explored before them.
Since being used as a contact list for ACT UP during the late '90s, the domain sat idle until Brothers purchased it in 2009.
Molesworth's rationale for doing the show had everything to do with a sense that the legacy of ACT UP had not survived its own moment.
ACT UP and other groups are similarly radically democratic and decentralized.
In his address, he noted the galvanic moral influence of ACT UP's forbidding SILENCE=DEATH logo, which he characterizes as "one of the effective works ever of graphic art." Clearly, Kushner is not silent.