An Etymological Dictionary of the German Language/Hermelin
Hermelin, m. and n. (accented like a foreign word), from the equiv. MidHG. hęrmelîn, n., ‘ermine,’ dimin. of MidHG. harme, OHG. harmo, m., ‘ermine’; a G. word merely, wanting in the other OTeut. languages, but in spite of the phonetic correspondence with Lith. szermǔ, ‘ermine’ (Lith. sz for Sans. ç, Aryan k, whence Teut. h), there is no doubt about its being genuinely Teut. From G. are derived the Rom. words similar in sound (ModFr. hermine, Ital. ermellino) rather than from the MidLat. mus armenius (for which the earlier mus ponticus is found).