be up in arms
US /bi ʌp ɪn ɑːrmz/
UK /bi ʌp ɪn ɑːrmz/

1.
sangat marah, protes keras
to be very angry and ready to protest strongly about something
:
•
The residents were up in arms about the proposed new factory.
Penduduk sangat marah tentang cadangan kilang baru itu.
•
My parents will be up in arms if I don't come home by midnight.
Ibu bapa saya akan sangat marah jika saya tidak pulang sebelum tengah malam.