An Etymological Dictionary of the German Language/Annotated/Firlefanz
Firlefanz, masculine, ‘nonsense, drollery,’ from Middle High German virlefanz, masculine, ‘a sort of dance,’ whence the meaning in Modern High German ‘foppish, silly manner.’ Some have tried to connect it with Norwegian fillefant, ‘scoundrel,’ fantefolk, ‘gipsies,’ which would make it akin to Fant. On account of the late appearance of the word it is impossible to decide, however, whether Anglo-Saxon fyrlen, ‘far, distant,’ is the basis of the first part of the compound, or rather Middle High German firlei, ‘a dance’ (French virelai, ‘virelay’). See Fant.