act up
US /ækt ʌp/
UK /ækt ʌp/

1.
bertingkah, berulah
behave badly or improperly
:
•
The children started to act up during the long car ride.
Anak-anak mulai bertingkah selama perjalanan mobil yang panjang.
•
If you act up again, you'll be sent to your room.
Jika kamu bertingkah lagi, kamu akan dikirim ke kamarmu.
2.
bermasalah, tidak berfungsi dengan baik
(of a machine or part of the body) fail to function properly
:
•
My old car always starts to act up in cold weather.
Mobil lamaku selalu mulai bermasalah saat cuaca dingin.
•
My knee has been acting up ever since I went for that long run.
Lututku bermasalah sejak aku lari jauh itu.