An Etymological Dictionary of the German Language/Milz
Milz, f., ‘milt, spleen,’ from the equiv. MidHG. milze, OHG. milzi, n.; from the HG. form are derived the Rom. cognates, Ital. milza, Span. melsa, ‘spleen.’ Corresponding forms are found in OIc. milte, n., AS. milte, n. and f.; E. milt and Du. milt signify both ‘spleen’ and ‘soft roe.’ The cognates are probably connected with the Teut. root melt (see Malz), ‘to soften, melt,’ “with respect to the properties ascribed to the spleen of manufacturing, decomposing, and liquefying the various humours of the body.” The term Milz is found in Teut. only; so too Hand, Finger, Daumen, Zehe, Leber, &c. The names of other parts of the body, such as Herz, Niere, Fuß, Arm, Rippe, have, however, a history that can be traced farther back.