Armageddon

The proper noun is from Middle English Hermagedon, from Old English Ermagedon, from Late Latin Harmagedōn, from Ancient Greek Ἁρμαγεδών (Harmagedṓn), used in the New Testament of the Bible (see the quotations) to render Hebrew הַר מְגִדּוֹ (har megído, “Mount Megiddo, the place where the final battle before the Last Judgment is predicted to occur”) from הַר (har, “mountain”) + מְגִידּוֹ (megído, “Megiddo or Meggidon, ancient city of Canaan”). The Bible does not directly refer to Mount Megiddo, but only to a plain (or “valley”) of Megiddo where the Egyptian pharaoh Necho II killed King Josiah of Judah during the Battle of Megiddo in 609 B.C.E. (2 Chronicles 35:20–24; see also 2 Kings 23:29), leading to “great mourning” (Zechariah 12:11). On the other hand, Revelation 19:17–19, which describes an angel calling birds to feed on the flesh of those who have died in the final battle, alludes to Ezekiel 38:17 in which God is described as calling on birds and animals to gather for Gog and Magog’s attack on Israel which will lead to “a great sacrifice upon the mountains of Israel, that ye may eat flesh and drink blood” (spelling modernized and emphasis added). Armageddon as the mountain of Megiddo appears to be a conflation of these two concepts.

The noun is derived from the proper noun.