An Etymological Dictionary of the German Language/Annotated/Lab

by Friedrich Kluge

Lab, neuter, rennet,’ from Middle High German lap(d), neuter, ‘rennet,’ also ‘acid fluid,’ Old High German lab, ‘broth’; it is not improbable, since the latter is the primary meaning, that the word is further cognate with Old Teutonic terms for ‘medicine.’ Gothic lubja, feminine, ‘poison,’ Anglo-Saxon lyb, ‘poison,’ Old Icelandic lyf, ‘medicine, Old High German luppi, neuter, ‘deadly juice.’ Note specially Middle High German kœseluppe, feminine, Old High German châsiluppa, Anglo-Saxon cŷs-lyb, equivalent to Middle High German kœ̂se-lap. The way in which Lab is related by gradation to lubja corresponds perhaps to that of High German Nase to Anglo-Saxon nosu, English nose. The primary meaning of the stem seems to be ‘strong, sharp perfume; plant juice’; Old Icelandic lyf, ‘medicine,’ and Gothic lubja, ‘poison,’ are differentiations of the same original sense.