acted up; acting up; acts up
1
: to act in a way different from that which is normal or expected: such as
a
: to behave in an unruly, recalcitrant, or capricious manner
the children were acting up
b
: show off
c
: to function improperly
this typewriter is acting up again
2
: to become active or acute after being quiescent
her rheumatism started to act up
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Examples of act up in a Sentence
Verb
the two-year-old was acting up in church so much that her dad had to take her outside
you should have seen the boys acting up when they put on their aprons
Recent Examples on the Web
Fran Hoepfner, Vulture, 12 Mar. 2025
In recent weeks, we are told that Phillips has at points been acting up for Moore after Moore broke her ankle while skiing, and she is understood to have been dipping her toe into drama.
—Max Goldbart, Deadline, 28 Feb. 2025
This includes Isla having to do damage control when the team’s star acts up off the court, and dealing with an overbearing parent of a player.
—Greg Rosenstein, NBC News, 27 Feb. 2025
Her pain can act up suddenly and seemingly comes without rhyme or reason.
—Matthew Futterman, The Athletic, 7 Mar. 2025
See All Example Sentences for act up
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Verb
The sisters may have spent weeks teasing the first single off their new album through several funny little videos and familiar-looking album art, but the tell-tale sign of new Haim music is when the weather gets good and people feel like acting up.
—Fran Hoepfner, Vulture, 12 Mar. 2025
In recent weeks, we are told that Phillips has at points been acting up for Moore after Moore broke her ankle while skiing, and she is understood to have been dipping her toe into drama.
—Max Goldbart, Deadline, 28 Feb. 2025
This includes Isla having to do damage control when the team’s star acts up off the court, and dealing with an overbearing parent of a player.
—Greg Rosenstein, NBC News, 27 Feb. 2025
Her pain can act up suddenly and seemingly comes without rhyme or reason.
—Matthew Futterman, The Athletic, 7 Mar. 2025
See All Example Sentences for act up
Cite this Entry
“Act up.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/act%20up. Accessed 24 Mar. 2025.
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