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
Relevance
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
Examples are automatically compiled from online sources to
show current usage.
Read More
Opinions expressed in the examples do not represent those of Merriam-Webster or its editors.
Send us feedback.
Recent Examples of act up
Some of the biggest names in Hollywood weren’t afraid to act up on Friday night.
—
Matt Donnelly, Variety, 10 Jan. 2026
And of course, Peterson not playing would have made some wonder if the McDonald’s All-American’s hamstring had acted up again.
—Gary Bedore, Kansas City Star, 7 Dec. 2025
But if your transmission acts up or your steering system goes haywire, car insurance won't help you.
—Alora Bopray, USA Today, 5 Dec. 2025
Its general sensibility seems more Superstore than The Office, down to the interstitial montages of customers acting up in the perpetually overcrowded waiting room.
—Angie Han, HollywoodReporter, 13 Oct. 2025
See All Example Sentences for act up
Matt Donnelly, Variety, 10 Jan. 2026
And of course, Peterson not playing would have made some wonder if the McDonald’s All-American’s hamstring had acted up again.
—Gary Bedore, Kansas City Star, 7 Dec. 2025
But if your transmission acts up or your steering system goes haywire, car insurance won't help you.
—Alora Bopray, USA Today, 5 Dec. 2025
Its general sensibility seems more Superstore than The Office, down to the interstitial montages of customers acting up in the perpetually overcrowded waiting room.
—Angie Han, HollywoodReporter, 13 Oct. 2025
See All Example Sentences for act up
Recent Examples of Synonyms for act up
Verb
-
The plaintiffs claim the administration is acting out of racial animus.—
Miami Herald Editorial Board,
Sun Sentinel,
6 Feb. 2026
-
Read on to find out why your child may be acting out, and when to seek help.—
Melissa Willets,
Parents,
5 Feb. 2026
Verb
-
Her voice is intimate and resonant, whether cut up into indistinct background flurries or pushed to the front of the mix.—
Alex Robert Ross,
Pitchfork,
13 Feb. 2026
-
Such a potato is cut up into sections, each having a sprout or two.—
David Beaulieu,
The Spruce,
9 Feb. 2026
Verb
-
Ashlyn, who will show off the back of her Vogue/CFDA Fashion Fund and Emerging Designer Award wins; and Daniella Kallmeyer, who was nominated for the CFDA’s American Womenswear Designer of the Year.—
Hilary Milnes,
Vogue,
10 Feb. 2026
-
Take Danielle Deadwyler, known as a dramatic heavyweight in award-winning projects like Till and The Piano Lesson, who gets to show off her goofier side here as Dylan, a poetry professor who becomes a wary confidante of Greg’s — and often steals the show.—
David Canfield,
HollywoodReporter,
9 Feb. 2026
Verb
-
Regulators also reviewed incidents in which the vehicles appeared to disobey traffic control devices.—
Kurt Knutsson,
FOXNews.com,
4 Feb. 2026
-
The country's Supreme Court of Justice removed him from office in 2017 and sentenced him to prison for disobeying a court order to remove barricades during protests against the government of then-President Nicolás Maduro.—
Patricia Gallagher Newberry,
Cincinnati Enquirer,
31 Jan. 2026
Verb
-
In April 2020, Iglesias shared a video of him horsing around with Lucy and Nicholas as the pair attempted to climb on his back for a ride.—
Andrea Wurzburger,
PEOPLE,
19 Jan. 2026
-
At this point in time, my little AI company, a lean and mean group of passionate believers, is horsing around fine-tuning the product, living on a couple of angel investments, where a 10X return on few million dollars is very satisfying, not only to the angel, but also to the employees.—
Neil Senturia,
San Diego Union-Tribune,
6 Oct. 2025
Verb
-
Casting two of the most smoldering contemporary actors on the planet clearly stacks the deck, and carries on the long tradition of pairing a dashing figure of brooding handsomeness (Laurence Olivier, Ralph Fiennes) with a breathless screen beauty (Merle Oberon, Juliette Binoche).—
David Fear,
Rolling Stone,
11 Feb. 2026
-
But last week, officials backtracked and announced that INDEC would carry on using the obsolete formula.—
Isabel Debre,
Fortune,
11 Feb. 2026
Cite this Entry
“Act up.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/act%20up. Accessed 14 Feb. 2026.
Copy CitationLove words? Need even more definitions?
Merriam-Webster unabridged
