text: Linguists believe that the etymology of the word either involves the Middle High German word lab ( to clot ) or the word laib ( loaf ) , and the Slavic root quas ( feast ) .
simplified: Some linguists say , that the word may be related to the German word lab , which means to clot , or the word Laib ( loaf ) . Perhaps it also contains the Slavic root quas ( yeast ) .