An Etymological Dictionary of the German Language/Schmetterling
Schmetterling, m., ‘butterfly,’ ModHG. only; in the earlier periods a term closely connected with ModHG. Falter (Zweifalter) is used. In most of the ModHG. dials. this literary term is also wanting; in Bav. müllermaler (so too in the Fulda dial.) or sommervogel, Suab. baufalter or weifalter. In other dials. occur Milchdieb, Molkendieb (Westph. also molkentövener, smantlecker), LG. Buttervogel or Butterfliege (AS. butorfleóge, E. butterfly), which may perhaps explain ModHG. Schmetterling. The latter term is probably derived from ModHG. Schmetten, ‘cream,’ which, like Schmetterling, is native to the eastern part of Middle Germany (see Schmant). Comp. further Du. vlinder.