An Etymological Dictionary of the German Language/Firlefanz
Firlefanz, m., ‘nonsense, drollery,’ from MidHG. virlefanz, m., ‘a sort of dance,’ whence the meaning in ModHG. ‘foppish, silly manner.’ Some have tried to connect it with Norw. 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 AS. fyrlen, ‘far, distant,’ is the basis of the first part of the compound, or rather MidHG. firlei, ‘a dance’ (Fr. virelai, ‘virelay’). See Fant.