An Etymological Dictionary of the German Language/Annotated/Blatter

by Friedrich Kluge

Blatter, feminine, ‘pock, pustule,’ from Middle High German blâtere, feminine, ‘bladder, pock,’ Old High German blâttara, feminine, ‘bladder’; compare Dutch blaar, Anglo-Saxon blœ̂dre, English bladder. The Gothic form would be *blêdrô (or bladrô? see Natter), with drô- as a suffix, corresponding to Greek τρα (see Ader, Natter); for blê as a root syllable see blasen, blähen.