Maybe Tubthumping, or perhaps LopadoÂtemachoÂselachoÂgaleoÂkranioÂleipsanoÂdrimÂhypoÂtrimmatoÂsilphio­araoÂmelitoÂkatakechyÂmenoÂkichlÂepiÂkossypho­hatto­eristerÂalektryonÂopteÂkephallioÂkigklo­eleioÂlagoioÂsiraioÂbapheÂtragano­terygon. The second is a made up word, but is the longest used in a work of fiction. It is used in Aristophanes comedy Assemblywoman, to describe a fictional dish in the book.