Observance of ceremony or special formality on important occasions. In the phrases with or in (great,etc.) solemnity. Now rare.

An occasion of ceremony; an observance or celebration of special importance; a festival or other similar occasion.

The action of solemnizing or celebrating in a ceremonial manner.

The action or practice of conforming to the requirements of prescribed rituals, ceremonies, etc.; spec. the performance of prescribed rites of…

solemnization.

Solemnization, celebration.

The action or an act of performing or observing a religious or formal rite or ceremony, spec. the Eucharist.

Religious observance. Obsolete. rare.

The action or an act of ministering in religious matters; service as a priest or minister. Now usually in plural.

The public observance of a religious or formal rite or ceremony, as a marriage, funeral, etc., with due form; the observance of a holy day…

The action of celebrating solemnly or ceremoniously.

The action of minister, v. (in various senses); ministration, administration; an instance of this.

Solemnization; solemn rite.

Solemnization.

The practice and performance of rites and ceremonies, worship, etc.; the right or permission to celebrate the observances (of a religion). †Formerly…

Devotional exercise; an act of public or private worship.

The action of officiating; performance of a religious, ceremonial, or public duty. Now rare.

Chiefly in the Roman Catholic Church: the action or process of being an altar server; the assisting of a priest during Mass.

The performance of ritual acts. Also in later use: repeated actions or patterns of behaviour having significance within a particular social group.