Strictly observant of or devoted to ceremony, ritual, or etiquette; punctilious: “borne on silvery trays by ceremonious world-weary waiters” (Financial Times)
Characterized by ceremony.
In accord with prescribed or customary usage; rigidly formal.
derivatives
ceŕe·móni·ous·ly
adverb
ceŕe·móni·ous·ness
noun
The American Heritage® Dictionary of the English Language, Fourth Edition