CEREMONIOUS
ceremonious, conventional
(adjective) rigidly formal or bound by convention; “their ceremonious greetings did not seem heartfelt”
pompous, ceremonious
(adjective) characterized by pomp and ceremony and stately display
Source: WordNet® 3.1
Etymology
Adjective
ceremonious (comparative more ceremonious, superlative most ceremonious)
Fond of ceremony, ritual or strict etiquette; punctilious
Characterized by ceremony or rigid formality
Source: Wiktionary
Cer`e*mo"ni*ous, a. Etym: [Cf. F. cérémonieux, L. Caerimoniosus.]
1. Consisting of outward forms and rites; ceremonial.
Note: [In this sense ceremonial is now preferred.]
The ceremonious part of His worship. South.
2. According to prescribed or customary rules and forms; devoted to
forms and ceremonies; formally respectful; punctilious. "Ceremonious
phrases." Addison.
Too ceremonious and traditional. Shak.
Syn.
– Formal; precise; exact. See Formal.
Source: Webster’s Unabridged Dictionary 1913 Edition