Synonyms of ceremonious in English:

dignified, majestic, imposing, impressive, solemn, stately

awe-inspiring, regal, imperial, elegant, grand, glorious, splendid, magnificent, resplendent, important, august, portentous

formal, courtly, punctilious, courteous, civil, deferential, stiff, rigid, affected

slow-moving, measured, deliberate, precise, scrupulous

informal starchy, just so