An Etymological Dictionary of the German Language/Annotated/Lauge
Lauge, feminine, ‘lye,’ from the equivalent Middle High German louge, Old High German louga, feminine; corresponding to Middle Low German lôge, Dutch loog, Anglo-Saxon leáh, and the equivalent English lye. In Old Icelandic laug, feminine, means ‘warm bath’ (preserved in Modern Icelandic in numerous proper names, and signifying ‘hot spring’). Perhaps this Teutonic word for ‘warm bath’ is connected with the Aryan root, low, lu, ‘to bathe’ (compare Latin lavâre), like the equivalent Swedish lut, of which an extended Aryan luk, equivalent to Teutonic luh, ‘to wash,’ may appear in Old High German luhhen, ‘to wash,’ Suabian lichen, North Franconian and Henneberg lüen, ‘to rinse washed linen.’ The High German word occurs in the Slavonic languages as lug, ‘lye.’