The Collaborative International Dictionary of English v.0.48:

Victorious \Vic*to"ri*ous\, a. [L. victoriosus: cf. F.
   victorieux. See Victory.]
   Of or pertaining to victory, or a victor; being a victor;
   bringing or causing a victory; conquering; winning;
   triumphant; as, a victorious general; victorious troops; a
   victorious day.
   [1913 Webster]

         But I shall rise victorious, and subdue
         My vanquisher.                           --Milton.
   [1913 Webster]

         Now are our brows bound with victorious wreaths.
                                                  --Shak.
   [1913 Webster] -- Vic*to"ri*ous*ly, adv. --
   Vic*to"ri*ous*ness, n.
   [1913 Webster]

WordNet (r) 3.0 (2006):

victoriously
    adv 1: in a victorious manner; "Virginia had defended her land
           victoriously"