1
as in to act out
to behave badly
the two-year-old was acting up in church so much that her dad had to take her outside
Synonyms & Similar Words
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Antonyms & Near Antonyms
2
as in to cut up
to engage in attention-getting playful or boisterous behavior
you should have seen the boys acting up when they put on their aprons
Synonyms & Similar Words
Example Sentences
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Recent Examples of act up
Meanwhile, the guests, who have literally just arrived five minutes ago, are already acting up.
—
Rafaela Bassili, Vulture, 10 Mar. 2026
Excess dust may also cause your allergies to act up.
—Madeline Buiano, Martha Stewart, 22 Feb. 2026
Koutouvides transitioned to life after football, found success in real estate development throughout Connecticut, but the pain of losing the Super Bowl twinges and acts up like an old joint injury.
—Dom Amore, Hartford Courant, 8 Feb. 2026
Likewise, when the young men started acting up, Josephine Holt took a keen interest in her newspaper.
—Literary Hub, 21 Jan. 2026
See All Example Sentences for act up
Rafaela Bassili, Vulture, 10 Mar. 2026
Excess dust may also cause your allergies to act up.
—Madeline Buiano, Martha Stewart, 22 Feb. 2026
Koutouvides transitioned to life after football, found success in real estate development throughout Connecticut, but the pain of losing the Super Bowl twinges and acts up like an old joint injury.
—Dom Amore, Hartford Courant, 8 Feb. 2026
Likewise, when the young men started acting up, Josephine Holt took a keen interest in her newspaper.
—Literary Hub, 21 Jan. 2026
See All Example Sentences for act up
Recent Examples of Synonyms for act up
Verb
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Friends and family say this isn't the first time in this trial Wright has acted out, from removing himself from the stand to missing court dates.—
WCCO Staff,
CBS News,
17 Apr. 2026
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This reality means that the environmental review angle can be an effective veto over development by NIMBY groups and others acting out of ideological rather than environmentally-conscious concerns.—
New York Daily News Editorial Board,
New York Daily News,
7 Apr. 2026
Verb
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Scalping the lawn can assist doveweed's spread by cutting up pieces that root all over the lawn.—
Brandee Gruener,
Southern Living,
11 Apr. 2026
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In the photo, Hat Rack is seen nestled within the weblike Sculpture for Traveling (1918), a net of rubber shower caps cut up and glued together that Duchamp took on a trip to Buenos Aires.—
Howard Halle,
ARTnews.com,
10 Apr. 2026
Verb
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Diane Kruger shows off the intricate details of her dress at the Tiffany & Co.—
Toria Sheffield,
PEOPLE,
21 Apr. 2026
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The teams are the best from Performance Cheer divisions ages 15 to 18 and show off their precision, artistry and athleticism.—
Eric Sondheimer,
Los Angeles Times,
20 Apr. 2026
Verb
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However, all of the city’s fire stations seemingly disobeyed the mayor by lowering their flags.—
R. Christian Smith,
Chicago Tribune,
14 Apr. 2026
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The Los Angeles County District Attorney's Office charged Nikolas Hart, 25, with six counts, including felony animal cruelty and misdemeanors related to allegations of domestic violence, witness tampering and disobeying a court order.—
Matthew Rodriguez,
CBS News,
7 Apr. 2026
Verb
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Bevel was horsing around with the Reverend James Orange and Andy Young in the courtyard under King's balcony, according to Orange.—
Gail Sheehy,
Vanity Fair,
20 Feb. 2026
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But Andrew continued to live at the home and was often seen riding his horse around Windsor Great Park and photographed waving to crowds.—
Martha Ross,
Mercury News,
12 Feb. 2026
Verb
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Lillo himself died in 2021, leaving Block to carry on his legacy.—
John Lauritsen,
CBS News,
16 Apr. 2026
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Sumner, Gilbert, and drummer Stephen Morris have carried on, while bassist Peter Hook quit to start his own ace live band, the Light, playing the exact same catalog on rival tours.—
Rob Sheffield,
Rolling Stone,
15 Apr. 2026
Cite this Entry
“Act up.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/act%20up. Accessed 21 Apr. 2026.
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