The Collaborative International Dictionary
maffick \maffick\ v. i. to celebrate publicly with boisterous rejoicing and hilarious and extravagant behavior. [Chiefly Brit.]
Douglas Harper's Etymology Dictionary
"to celebrate boisterously," 1900, from Mafficking, a nonce-verb formed punningly from Mafeking, British garrison town in South Africa whose relief on May 17, 1900, during the Boer War, was celebrated wildly in London. OED reports the word "confined to journalistic use." By now it might as well write, "confined to dictionaries." The place name (properly Mafikeng) is from Tswana and is said to mean "place of rocks," from mafika, plural of lefika "rock, cliff" + -eng "place of."
Wiktionary
vb. (context intransitive English) To celebrate in a boisterous manner.
Usage examples of "maffick".
Without the squeeze of crowds, the jibes of detractors, the mad mephitic mafficking of traffic, perhaps he was both more focused and less restrained.
He joined the mafficking clubbers, hiding himself within their colourful nucleus, crossing the road by the London Coliseum to head towards Piccadilly Circus.