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
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
Sturm said his back started acting up after the team’s first practice.
—Michael Russo, New York Times, 1 Oct. 2025
See All Example Sentences for act up
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
Sturm said his back started acting up after the team’s first practice.
—Michael Russo, New York Times, 1 Oct. 2025
See All Example Sentences for act up
Recent Examples of Synonyms for act up
Verb
-
The actors joked about how trying to put on medical gloves quickly enough while remembering and acting out dialogue can make scenes go sideways in a heartbeat.—
Georg Szalai,
HollywoodReporter,
30 Dec. 2025
-
Ordained to the Catholic priesthood in June, Jimenez was watching as parishioners acted out the Nativity scene during a posada, a Latin American tradition that reenacts Mary and Joseph’s journey to Bethlehem in search of shelter.—
Alex Riggins,
San Diego Union-Tribune,
25 Dec. 2025
Verb
-
By the third period, with his nose cut up, Kesselring was on the ice in the final minute of the game, helping to get it to overtime.—
Matthew Fairburn,
New York Times,
17 Jan. 2026
-
To meet that goal, the grantmaker will cut up to 500 of its 2,375 staff positions by 2030, including some open roles that may remain unfilled.—
Stephanie Beasley,
Fortune,
14 Jan. 2026
Verb
-
People confirmed the news on January 24 after Mariano shared a photo of herself holding their first child, daughter Ke'ala Coral, in a bikini that appeared to show off her growing bump.—
Meg Walters,
InStyle,
25 Jan. 2026
-
That’s the fun discovery meteorologist Jennifer McDermed showed off in a post on X last week, amid severe winter weather across much of the country.—
Adam Carlson,
PEOPLE,
25 Jan. 2026
Verb
-
But German General Dietrich von Choltitz is credited with disobeying Hitler’s command.—
Sally Susman,
Time,
27 Jan. 2026
-
When should troops disobey their superiors?—
TheWeek,
TheWeek,
23 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
-
Honda has also generated a lot of buzz with its new CB1000F homage (below) to the beloved CB750F from the 1980s, and many of Harley-Davidson’s models carry on the looks and stance of models stretching back to the 1950s.—
William Roberson,
Forbes.com,
29 Jan. 2026
-
Over the weekend, business leaders offered a mix of responses after federal agents shot Alex Pretti in Minneapolis, revealing yet again how one of America’s most powerful cohorts is — publicly, at least — carrying on with business as usual.—
Allison Morrow,
CNN Money,
27 Jan. 2026
Cite this Entry
“Act up.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/act%20up. Accessed 31 Jan. 2026.
Copy CitationLove words? Need even more definitions?
Merriam-Webster unabridged
