act up

acted up; acting up; acts up

Definition of act up

 (Entry 1 of 2)

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
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
\ ˈakt-ˈəp How to pronounce ACT UP (audio) \

Definition of ACT UP (Entry 2 of 2)

AIDS Coalition to Unleash Power

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Synonyms for act up

Synonyms: Verb

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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

First Known Use of act up


1879, in the meaning defined at sense 1

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Time Traveler for act up

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The first known use of act up was in 1879

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Cite this Entry

“Act up.” Dictionary, Merriam-Webster, Accessed 25 Jan. 2021.

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