Synonyms to in due form

solemnly, bleakly, ceremoniously, decorously, demurely, dismally, drearily, earnestly, formally, funereally, gloomily, grandly, gravely, grimly, heavily, imposingly, in set form, loftily, magisterially, majestically, nobly, pro forma, regally, ritualistically, ritually, royally, sadly, sedately, seriously, sober-mindedly, soberly, sobersidedly, somberly, sombrously, staidly, stately, thoughtfully, venerably, with dignity, worthily