possible sources alteration of huzzah. This is however questionable. Another plausible etymology is from Turkic war cry урра(urra), which means encircle or surround in Tatar, made its way to Slavic languages as ура(urá) in 12-13 century, and later to the languages: hurra in German, Danish, Swedish and Norwegian and húrra in Icelandic.
Full definition of hooray
Interjection
Used to express approval, joy or victory.Lizzie has broken a world record, and is now an Olympic medallist! – Hooray!