An Etymological Dictionary of the German Language/Lebkuchen
Lebkuchen, m., ‘gingerbread,’ from the equiv. MidHG. lëbekuocke, m., allied to the equiv. MidHG. lëbezelte. The derivation of lëb-, from Slav. lipa, ‘lime-time,’ Pol. lipiec, ‘finest honey (lime-tree honey),’ is improbable; Lat. lîbum, too, hardly suffices to explain the HG. word. MidHG. lëbe- is more probably a graded form of MidHG. leip (see Laib), ‘bread.’ Or is it connected with ModSlov. lepenj, ‘a sort of cake’?