Source : Webster's Revised Unabridged Dictionary (1913)

Soberly \So"ber*ly\, adv.
   In a sober manner; temperately; cooly; calmly; gravely;
   seriously.

Soberly \So"ber*ly\, a.
   Grave; serious; solemn; sad. [Obs.]

         [He] looked hollow and thereto soberly.  --Chaucer.

Source : WordNet®

soberly
     adv : in a grave and sober manner; "he walked soberly toward the
           altar" [syn: {gravely}, {staidly}]