DECORUM
decorum, decorousness
(noun) propriety in manners and conduct
Source: WordNet® 3.1
Etymology
Noun
decorum (countable and uncountable, plural decorums)
(uncountable) Appropriate social behavior; propriety
(countable) A convention of social behavior
Source: Wiktionary
De*cor"um, n. Etym: [L. dec, fr. dec. See Decorous.]
Definition: Propriety of manner or conduct; grace arising from suitableness
of speech and behavior to one's own character, or to the place and
occasion; decency of conduct; seemliness; that which is seemly or
suitable.
Negligent of the duties and decorums of his station. Hallam.
If your master Would have a queen his beggar, you must tell him, That
majesty, to keep decorum, must No less beg than a kingdom. Shak.
Syn.
– Decorum, Dignity. Decorum, in accordance with its etymology, is
that which is becoming in outward act or appearance; as, the decorum
of a public assembly. Dignity springs from an inward elevation of
soul producing a corresponding effect on the manners; as, dignity of
personal appearance.
Source: Webster’s Unabridged Dictionary 1913 Edition