An Etymological Dictionary of the German Language/Annotated/Filz
Filz, masculine, ‘felt, blanket; miser; reprimand,’ from the equivalent Middle High German vilz, Old High German filz, masculine; compare Dutch vilt, Anglo-Saxon and English felt, Swedish and Danish filt, ‘felt’ (Gothic *filtis, pre-Teutonic *peldos, neuter). Latin pilus, pileus, Greek πῖλος, are scarcely allied; it is more probably connected with Old Slovenian plŭstĭ, ‘felt.’ From the Teutonic word are derived the similarly sounding Romance words, Italian feltro, French feutre, Middle Latin filtrum, ‘felt.’ Other words also relating to weaving were introduced into Romance from Teutonic. See Haspe, Rocken.