In Norse mythology Odin is the highest of the gods, presiding over war, wisdom and death. He is the husband of Frigg and resides in Valhalla, where warriors go after they are slain. He is usually depicted as a one-eyed older man, carrying two ravens on his shoulders who inform him of all the events of the world. At the time of Ragnarök, the final battle, it is told that he will be killed fighting the great wolf Fenrir.
This is not the usual spelling in any of the Scandinavian languages (in Sweden and Denmark it is Freja and in Norway it is Frøja) but it is the common spelling of the goddess's name in English. In the 2000s it became popular in Britain.