Huzzah is a shout used to express joy, encouragement, or triumph.
Usually shouted after something impressive or joyous has occured, such as a spectacular kill in a tournament, an announcement in court, or simply whenever you feel the urge. It tends to replace applauding and cheering, or is sometimes accompanied with the stomping of feet. This word has lead to such things as the creation of the "Huzzah song".
NB - Not all kingdoms use "Huzzah". The West Kingdom and many kingdoms descended from it (An Tir, Atenveldt, Caid, Outlands, and Lochac) use huzzah. Other kingdoms have shouts like vivat, hoobah, and wassail.