Source : Webster's Revised Unabridged Dictionary (1913)

Zealous \Zeal"ous\ (?; 277), a. [LL. zelosus. See {Zeal}.]
   1. Filled with, or characterized by, zeal; warmly engaged, or
      ardent, in behalf of an object.

            He may be zealous in the salvation of souls. --Law.

   2. Filled with religious zeal. [Obs.] --Shak. --
      {Zeal"ous*ly}, adv. -- {Zeal"ous*ness}, n.

Source : WordNet®

zealously
     adv : in a zealous manner; "she worked zealously to raise funds
           for the literacy project"