An Etymological Dictionary of the German Language/Annotated/Mond
Mond, masculine, ‘moon,’ from Middle High German mâne, masculine, ‘moon, month’ (Middle High German rarely feminine), Old High German mâno, masculine, ‘moon’; even in Middle High German occurs a form with a final dental, mânt, mânde, which is due to confusion with mânet (yet compare Elentier and niemand), Gothic mêna, Anglo-Saxon môna, masculine, English moon, Dutch maan. In the form mêno, masculine, a common Teutonic term for ‘moon’ (a later feminine form appears in Middle High German mœnîn, Old High German mânîn); it is based, like most of the terms for ‘moon’ and ‘month’ in the cognate Aryan languages, on Aryan mên, mênôt, or mênes. Compare Sanscrit mâs, masculine (for mâis, mêns), ‘moon, month,’ mâsa, masculine, ‘month,’ Greek μήν (for *μήνς), ‘month,’ Latin mensis, ‘month,’ Old Slovenian měsęcĭ, masculine, ‘moon, month,’ Lithuanian měnů, ‘moon,’ měnesis, ‘month,’ Old Irish mí. The exact relation of Teutonic mênôþ-, mênan-, to Latin-Greek mêns- (*mênes-) is disputed. The derivation of the stems mên, mêns, from the Aryan root mē̆, ‘to measure’ (Sanscrit mâ, ‘to measure, mete out,’ mâtram, Greek 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. Compare Monat and Montag.