solemnity

plural solemnities

1. countableuncountableThe quality of being deeply serious and sober or solemn.

   the solemnity of a funeral

   3 more examples

   The stateliness and gravity of the Spaniards shows itself in the solemnity of their language.

   1711 August 14 (Gregorian calendar), [Joseph Addison; Richard Steele et al.], “FRIDAY, August 4, 1711”, in The Spectator, number 158; republished in Alexander Chalmers, editor, The Spectator; a New Edition, […], volume II, New York, N.Y.: D[aniel] Appleton & Company, 1853, →OCLC

   These promises were often made with great solemnity and confirmed with an oath.

   1754, Jonathan Edwards, An Inquiry into the Modern Prevailing Notions Respecting that Freedom of the Will which is supposed to be Essential to Moral Agency

   There has been nothing in archæology that has made such a vivid impression on the popular imagination as Mr. Arthur Evans's excavations at Knossos. The Minotaur! the Labyrinth—such words do not suggest the solemnities of antiquarian research.

   1907, Ronald M. Burrows, The Discoveries In Crete, page 1

   Synonyms: gravity

2. countableuncountableAn instance or example of solemn behavior; a rite or ceremony performed with reverence.

   Great was the cauſe; our old ſolemnities / From no blind zeal or fond tradition riſe, / But ſav'd from death, our Argives yearly pay / Theſe grateful honours to the God of Day.

   c. 1699 – 1703, Alexander Pope, “The First Book of Statius His Thebais”, in The Works of Mr. Alexander Pope, volume I, London: […] W[illiam] Bowyer, for Bernard Lintot, […], published 1717, →OCLC, page 337

   1 more example

   This is the Man after God's Heart, […] by endeavouring, when he aſſiſted at thoſe Solemnities, to perform them with the utmoſt Attention, Alacrity, and holy Warmth of Mind, of which he was capable.

   1698 December 1 (Gregorian calendar), Francis Atterbury, “The Usefulness of Church Musick, a Sermon Preached on St. Cecilia’s Day, in 1698”, in Thomas Moore, editor, Sermons on Several Occasions. […], volume II, London: […] George James […]; and sold by C. Davis, […], published 1734, →OCLC, pages 233–234

3. countableuncountableCatholicismA feast day of the highest rank celebrating a mystery of faith such as the Trinity, an event in the life of Jesus, the Virgin Mary, or another important saint.
4. countableuncountablelawA solemn or formal observance; proceeding according to due form; the formality which is necessary to render a thing done valid.
5. countableobsoleteuncountableA celebration or festivity.