As in the rainbow bridge from Asgard the realm of the gods to Earth, in nordic mythology. I recently looked it up expecting it to have some connection to the word “frost”, but instead I found the following:
[<Icel Bifröst =bif- (root of bifa. c OE bifian to shake) + röst, c. OHG rasta stretch of road.]
So it’s more or less “shaky path”? I now have this vision of Asgard being surrounded by a cosmically wide and deep chasm, with only a narrow shaky plank to get across. Clearly Odin does NOT like candy sellers and Jehovah’s Witnesses knocking at the door.
He doesn’t like ice giants knocking on his door, either. Although Bifrost isn’t much of a deterrant, I don’t think, considering how many of them made it into Asgard to steal Mjolnir, offer to build new gates, complain to the manager about so-and-so killing so-and-so, or proposition Thor’s daughter (although that was actually a dwarf, IIRC). Heimdall is supposed to be guarding the bridge but judging by all the giants wandering in and out either Asgard has a liberal open-door policy or Heimdall just doesn’t care unless you’ve got an army with you.
Yes, Bifrost is from “quivering road”, or “flaming bridge”, but that is not 100% certain. Bifrost is pictured as the rainbow or the Milky Way.
It is the bridge that leads from the earth to the realm of the gods, Asgård. Heimdall lives at the bridgehead, according to Snorre Sturlason.
Heimdall is a very complex and interesting god; perhaps the most mysterious of the aesir. The name seems to come from ‘world’ and ‘tree’, which suggest that he is an identification of the Yggdrasil, and a very old sky god.
Snorre Sturlason calls him “the White God”, who lives in “the Sky Mountains” at Bifrost — which might be the rainbow, the Milky Way, or the world tree — as some kind of guardian.
He has teeth is of gold and his horse is called ‘Gold top’, and he has other attributes of a sky father, sun god too.
In some sources, as the Poetic Edda, he is the son of nine mothers and father of all.
The image of him watching the bridge, is derived particularly from him blowing his horn when the armies of Loke, and Ragnarök is approaching.