Source : Webster's Revised Unabridged Dictionary (1913)

Successful \Suc*cess"ful\, a.
   Resulting in success; assuring, or promotive of, success;
   accomplishing what was proposed; having the desired effect;
   hence, prosperous; fortunate; happy; as, a successful use of
   medicine; a successful experiment; a successful enterprise.

         Welcome, nephews, from successful wars.  --Shak.

   Syn: Happy; prosperous; fortunate; auspicious; lucky. See
        {Fortunate}. -- {Suc*cess"ful*ly}, adv. --
        {Suc*cess"ful*ness}, n.

Source : WordNet®

successful
     adj : having succeeded or being marked by a favorable outcome; "a
           successful architect"; "a successful business venture"
           [ant: {unsuccessful}]