Source : Webster's Revised Unabridged Dictionary (1913)

Hurrah \Hur*rah"\ Hurra \Hur*ra"\, interj. [Cf. G., Dan., & Sw.
   hurra. Cf. {Huzza}.]
   A word used as a shout of joy, triumph, applause,
   encouragement, or welcome.

         Hurrah! hurrah! for Ivry and Henry of Navarre.
                                                  --Macaulay.