An Etymological Dictionary of the German Language/Annotated/März

by Friedrich Kluge

März, masculine, from the equivalent Middle High German męrze, masculine, Old High German męrzo, marzeo, masculine, ‘March,’ from Latin (mensem) Martium. The corresponding Westphalian märte, Middle Low German męrte, as well as Dutch maart, make it probable that März was borrowed previous to the Old High German permutation of consonants about the era of the Merovings, and in fact contemporaneously with August, Jänner, and Mai. English March, Mid. marche, was borrowed at a some what later period from Old Irish march (Modern French mars).