From Longman Dictionary of Contemporary Englishbe up in armsbe up in armsANGRYto be very angry and ready to argue or fight Residents are up in arms about plans for a new road along the beach. → arm
Examples from the Corpus
be up in arms• Mavis Bramley was up in arms about the woman from Oldham.• John Adams decided that everyone but Episcopalians was up in arms against the new tax law.• And already fans are up in arms.• Yet some big securities houses are up in arms over the Elwes report.• The association's members were up in arms.• But it will never be, for already the politicians are up in arms against it.• Pine Valley residents are up in arms about plans to build a prison in the area.• Residents are up in arms about plans for a new road along the beach.• Civil libertarians would be up in arms but it would mean fewer animals whose final romp is into a killing-room.• Those people would be up in arms. 