Mimir. The name of the wise giant keeper of the holy well Mimis-brunnr, the burn of Mimer, the well of wisdom, at which Odin pawned his eye for wisdom; a myth which is explained as symbolical of the heavenly vault with its single eye, the sun, setting in the sea.
Mjolnir. Thor's formidable hammer. After Ragnarok, it is possessed by his sons Mode and Magne. Mjolner.
Mistilteinn [Eng. mistletoe]. The mistletoe or mistletwig, the fatal twig by which Balder, the white sun-god, was slain. After the death of Balder, Ragnarok set in. Balder's death was also symbolical of the victory of darkness over light, which comes every year at midwinter. The mistletoe in English households at Christmas time is no doubt a relic of a rite lost in the remotest heathendom, for the fight of light and darkness at midwinter was a foreshadowing of the final overthrow in Ragnarok. The legend and the word are common to all Teutonic peoples of all ages. Mistletoe.
Modi [Courage]. A son of Thor. Mode.
Modsognir. The dwarf highest in degree or rank. Modsogner.
Moinn. A serpent under Ygdrasil. Moin.
Mundilfari. Father of the sun and moon. Mundilfare.
Muninn [Memory]. One of Odin's ravens. Munin.
Muspell. The name of an abode of fire. It is populated by a host of fiends, who are to appear at Ragnarok and destroy the world by fire. Muspel.
Muspellsheimr. The abode of Muspel. This interesting word (Muspell) was not confined to the Norse mythology, but appears twice in the old Saxon poem Heliand. In these instances muspel stands for the day of judgment, the last day, and answers to Ragnarok of the Norse mythology.