What does "decorous" mean?

Decorous: Suitable to a character, or to the time, place, and occasion; marked with decorum; becoming; proper; seemly; befitting; as, a decorous speech; decorous behavior; a decorous dress for a judge. A decorous pretext the war. Motley. -- De*co"rous*ly, adv. -- De*co"rous*ness, n.