ceremonial

American Heritage® Dictionary of the English Language, Fourth Edition

1. adj. Of, appropriate to, or characterized by ceremony; formal or ritual.
2. adj. Involved or used in ceremonies: ceremonial garb.
3. n. A set of ceremonies prescribed for an occasion; a ritual.
4. n. A ceremony or rite.

Century Dictionary and Cyclopedia

1. Relating to ceremonies or external forms or rites: ritual; pertaining to or consisting in the observance of set forms or formalities.
2. Specifically Pertaining to the forms and rites of the Jewish religion: as, the ceremonial law, as distinguished from the moral law.
3. Observant of forms; precise in manners; formal: as, “the dull, ceremonial track,”
4. Synonyms Ceremonious, Formal, etc. See ceremonious.
5. n. A system of rites or ceremonies enjoined by law or established by custom, as in religious worship, social intercourse, etc.; rites, formalities, or requirements of etiquette, to be observed on any special occasion.
6. n. Specifically The order for rites and forms in the Roman Catholic Church, or the book containing the rules prescribed to be observed on solemn occasions.
7. n. A prehistoric stone implement-supposed to have been used for ceremonial purposes.

Wiktionary

1. adj. Of, relating to, or used in a ceremony; ritual or formal.
2. n. A ceremony, or series of ceremonies, prescribed by ritual.

GNU Webster's 1913

1. adj. Relating to ceremony, or external rite; ritual; according to the forms of established rites.
2. adj. Observant of forms; ceremonious. [In this sense ceremonious is now preferred.]
3. n. A system of rules and ceremonies, enjoined by law, or established by custom, in religious worship, social intercourse, or the courts of princes; outward form.
4. n. The order for rites and forms in the Roman Catholic church, or the book containing the rules prescribed to be observed on solemn occasions.

WordNet 3.0

1. adj. marked by pomp or ceremony or formality
2. n. a formal event performed on a special occasion