decorum

Noun

decorum (countable and uncountable, plural decora or decorums)

1. (uncountable) Appropriate social behavior.
   • Everyone was assembled in the dining-room. Under the circumstances, we were naturally not a cheerful party. The reaction after a shock is always trying, and I think we were all suffering from it. Decorum and good breeding naturally enjoined that our demeanour should be much as usual, yet I could...1920, Agatha Christie, The Mysterious Affair at Styles, London: Pan Books, published 1954, page 57
   • It was sort of a finishing school. You know, to teach proper social decorum and so on and so forth.2010, Pseudonymous Bosch (pseudonym; Raphael Simon), This Isn't What It Looks Like, ch. 4

   Synonyms:

   decency, courtesy, propriety, etiquette

2. (countable) A convention of social behavior.
   • In the architecture and embellishments of the chamber, the evident design was to dazzle and astound. Little attention had been paid to the decora of what is technically called “keeping,” or to the proprieties of nationality. The eye wandered from object to object, and rested upon none; neither the...1834 January, [Edgar Allan Poe], “The Visionary”, in The Lady’s Book, page 41, column 2