Y is not a huge day for the Old Norse theme, although at least two of the words are pretty significant.
Y is for Yggdrasil, the "World Tree" which literally means "Steed of Ygg", which may be a by-name of Odin, in which case Yggdrasil would be the tree from which he hung as a sacrifice for nine nights to learn the runes presumably. Yggdrasil is an Ash tree and the Aesir go there daily to make judgments. A dragon gnaws at it's roots, a stag eats it's leaves; it connect all of the nine worlds.
Y is for Ymir, the primal giant from whom almost all life sprung. The entire universe is made from his body, before him there was nothing. Giants were born from his sweat, dwarves from the maggots that swarmed upon his dead flesh. The gods were related having been born from the great cosmic Cow Audhumla, who licked Buri, the first of the Aesir, from the ice of Ginnungagap, where Ymir also spontaneously formed. Either way, Ymir is the father (and mother) of the race of Jötnar, and also a forefather, presumably of the races of both the Aesir and the Vanir, since Audhumla only licked Buri from the ice, and both Ymir and Buri were nourished by her milk. Eventually, Ymir was killed, possibly by Odin, and his body was used to create the universe and pretty much everything in it.
Y is for Yngvi, which is another name for Frey, who is sometimes called Yngvi-Frey.
I didn't actually get to go to the gaming convention I have been pimping here on my blog today, apparently buying a new vehicle drains all your excess "fun" funds away, so I hope that anyone who did get a chance to go to Arcon XI had a good time. It kind of bums me out too that I pre-cancelled my B/X game for tomorrow for the convention and now I can't go, but I guess that's the breaks when you are a grown up. Maybe I'll actually get around to painting some miniatures tomorrow?