act up
[verb]
Synonyms: cut up, carry on, horse, horseplay

[TahlilGaran] English Synonym Dictionary ▲

act up phrasal verb (see also act)

1. if children act up, they behave badly:
He’s a tough kid and he acts up a lot.

2. if a machine or part of your body acts up, it does not work properly:
The computer is acting up again.

[TahlilGaran] Dictionary of Contemporary English ▲

ˈAct-Up
an organization in the US and the UK that demands more help and support for people with AIDS. It is known for its strong active protests against companies or government departments if they treat people with AIDS unfairly.

[TahlilGaran] Dictionary of Contemporary English ▲

act up
1.
to behave badly.
Sometimes kids act up because they just want attention.

Usage notes: usually used to refer to children
2.
to operate badly.
My computer began acting up and I lost a whole day's work.

3.
to become active.
Her allergies acted up when she went hiking in the woods.

Usage notes: usually used to refer to a medical condition

[TahlilGaran] English Idioms Dictionary ▲

act up
to misbehave
The children began to act up during the field trip.

[TahlilGaran] English Idioms Dictionary ▲

act up
v., informal
1. To behave badly; act rudely or impolitely.
The dog acted up as the postman came to the door.
2. To work or run poorly (as a after all machine); skip; miss.
The car acted up because the spark plugs were dirty.

[TahlilGaran] English Idioms Dictionary ▲