Merriam-Webster's Word of the Day for May 17, 2012 is:

maffick • \MAF-ik\  • verb
: to celebrate with boisterous rejoicing and hilarious behavior

Examples:
Fans mafficked for hours outside the stadium, celebrating the team's dramatic victory in the division championship.

"In half an hour, after the mildest of mafficking, the last visitors of the exhibition's last day had gone out of the gates and the staff began their final acts of closing up shop." — From an article in The Guardian (London), October 1, 2011

Did you know?
"Maffick" is an alteration of Mafeking Night, the British celebration of the lifting of the siege of a British military outpost during the South African War at the town of Mafikeng (also spelled Mafeking) on May 17, 1900. The South African War was fought between the British and the Afrikaners, who were Dutch and Huguenot settlers originally called Boers, over the right to govern frontier territories. Though the war did not end until 1902, the lifting of the siege of Mafikeng was a significant victory for the British because they held out against a larger Afrikaner force for 217 days until reinforcements could arrive. The rejoicing in British cities on news of the rescue produced "maffick," a word that was popular for a while, especially in journalistic writing, but is now relatively uncommon.