In light of the upcoming Biblical month of Bul (I Melakhim 6:38), known to us as Marcheshvan, I remembered an interesting article in Jewish Action a few years ago by Rabbi Ari Z. Zivotofsky about the origin of the term for this month. Pointing out how in Akkadian the waw and mem sounds interchanged, 'Marcheshvan', in Babylonian, derived from Akkadian 'w'rach sh'man' which is cognate of the Hebrew 'yerech shemini,' or 'eight month'. You know, like our ineptly named 10th month October. Zivotofsky speculates that the Yemenite Jewish pronunciation of something like 'M'rachsh'wan' might be closer to the original than the Marcheshvan of Ashkenazi tradition. He also discusses the popular folk etymology which holds that the month is really called Cheshvan, with 'mar', meaning 'bitter' in Hebrew an addition much like 'menachem' is often popularly added to 'Av'. Various reasons were given why Cheshvan is 'bitter', including that this is the only month without some sort of holy-day, Biblical or rabbinic. Naturally this is what I was taught as a child, so what else is new. The posekim permit either Marcheshvan or Cheshvan in legal documents, because popular use has made even Cheshvan correct. Languages develop, you know.