act up

1 of 2

verb

acted up; acting up; acts up

intransitive verb

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
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

ACT UP

2 of 2

abbreviation

AIDS Coalition to Unleash Power

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
Verb
But in 1954, Brando was at the height of his talents, bringing American acting up to and past to the British standard for the first time, with a realism achieved through that delicate balancing of gender qualities that pretty much no one before or after mastered in the same way. Allen Farmelo, Robb Report, 23 July 2024 Babies remain the last vestige of scoundrels in sequel terms, so naturally the movie introduces a son to Gru (voiced as usual by Steve Carell) and Lucy (Kristen Wiig) who, semi-amusingly, can’t stand his dad, screaming or acting up in some other way every time Gru picks him up. Brian Lowry, CNN, 2 July 2024 Nobody's that good an actor to keep this act up for 50 years. Daniela Avila, Peoplemag, 27 June 2024 The parents of children who act up in the Jersey Shore town of Margate City will be fined this summer for their badly behaved kids. Brian Niemietz, New York Daily News, 13 June 2024 See all Example Sentences for act up 

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'act up.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

First Known Use

Verb

1879, in the meaning defined at sense 1

Time Traveler
The first known use of act up was in 1879

Dictionary Entries Near act up

Cite this Entry

“Act up.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/act%20up. Accessed 2 Nov. 2024.

Kids Definition

act up

verb
: to act in an unruly, abnormal, or annoying way
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