Source : Webster's Revised Unabridged Dictionary (1913)

Solemnity \So*lem"ni*ty\, n.; pl. {Solemnities}. [L. solemnitas,
   solennitas: cf. F. solennit['e], solemnit['e], OF. also
   sollempnit['e].]
   1. A rite or ceremony performed with religious reverence;
      religious or ritual ceremony; as, the solemnity of a
      funeral, a sacrament.

            Great was the cause; our old solemnities From no
            blind zeal or fond tradition rise, But saved from
            death, our Argives yearly pay These grateful honors
            to the god of day.                    --Pope.

   2. ceremony adapted to impress with awe.

            The forms and solemnities of the last judgment.
                                                  --Atterburry.

   3. Ceremoniousness; impressiveness; seriousness; grave
      earnestness; formal dignity; gravity.

            With much glory and great solemnity.  --Chaucer.

            The statelines and gravity of the Spaniards shows
            itself in the solemnity of their language.
                                                  --Addison.

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

   4. Hence, affected gravity or seriousness.

            Solemnity 's a cover for a sot.       --Young.

   5. Solemn state or feeling; awe or reverence; also, that
      which produces such a feeling; as, the solemnity of an
      audience; the solemnity of Westminster Abbey.

   6. (Law) A solemn or formal observance; proceeding according
      to due form; the formality which is necessary to render a
      thing done valid.

Source : WordNet®

solemnity
     n 1: a trait of dignified seriousness [syn: {sedateness}, {staidness},
           {solemness}]
     2: a solemn and dignified feeling [syn: {gravity}] [ant: {levity}]