An Etymological Dictionary of the German Language/Mond
Mond, m., ‘moon,’ from MidHG. mâne, m., ‘moon, month’ (MidHG. rarely fem.), OHG. mâno, m., ‘moon’; even in MidHG. occurs a form with a final dental, mânt, mânde, which is due to confusion with mânet (yet comp. Elentier and niemand), Goth. mêna, AS. môna, m., E. moon, Du. maan. In the form mêno, m., a common Teut. term for ‘moon’ (a later fem. form appears in MidHG. mœnîn, OHG. mânîn); it is based, like most of the terms for ‘moon’ and ‘month’ in the cognate Aryan languages, on Aryan mên, mênôt, or mênes. Comp. Sans. mâs, m. (for mâis, mêns), ‘moon, month,’ mâsa, m., ‘month,’ Gr. μήν (for *μήνς), ‘month,’ Lat. mensis, ‘month,’ OSlov. měsęcĭ, m., ‘moon, month,’ Lith. měnů, ‘moon,’ měnesis, ‘month,’ OIr. mí. The exact relation of Teut. mênôþ-, mênan-, to Lat.-Gr. mêns- (*mênes-) is disputed. The derivation of the stems mên, mêns, from the Aryan root mē̆, ‘to measure’ (Sans. mâ, ‘to measure, mete out,’ mâtram, Gr. μέτρον, ‘measure,’ see Mahl, messen), may accord with the facts of the case (the moon was regarded as the measurer of time), yet from the historical and linguistic standpoint it cannot be considered a certainty. Comp. Monat and Montag.