(a.) 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.

Christian accepted according to Hoyle acknowledged admitted appropriate approved au fait becoming befitting being done ceremonial ceremonious civil civilized comely comme il faut condign conformable conforming conventional correct customary de rigueur decent delicate demure dignified done due earnest elegant felicitous fit fitting formal frowning genteel gentlemanly good grave grim grim-faced grim-visaged happy hieratic kosher ladylike liturgic long-faced mannerly meet modest nice normal normative orthodox polished polite pompous prim proper punctilious received recognized refined respectable right right and proper righteous rightful rigid ritual ritualistic sacerdotal seasonable sedate seemly serious sober sober-minded sobersided solemn somber staid stately stiff stone-faced straight-faced stuffy suitable thoughtful traditional unsmiling urbane weighty well-behaved well-mannered