From Longman Dictionary of Contemporary Englishdecorumde‧co‧rum /dɪˈkɔːrəm/ noun [uncountable] BEHAVE formal behaviour that shows respect and is correct for a particular situation, especially a formal occasion He was disciplined for breaching the Senate’s rules of decorum.
Examples from the Corpus
decorum• These events will most likely be models of decorum, friends who are planning them said Wednesday.• Chauvin lacks a sense of decorum in professional matters.• Despite the foulest weather, the Traction acquitted itself with perfect decorum.• The ladies were in the middle doing their social best to preserve decorum.• Most days are lost in the decorum of trying, lost in the lanes of the almost known.• They nourish the spirit in a way decorum never could.Origin decorum (1500-1600) Latin decorus; → DECOROUS 