 Scholar Andy Orchard posits that Bifröst may mean " shimmering path . " He notes that the first element of Bilröst — bil ( meaning " a moment " ) — " suggests the fleeting nature of the rainbow , " which he connects to the first element of Bifröst — the Old Norse verb <unk> ( meaning " to shimmer " or " to shake " ) — noting that the element provokes notions of the " lustrous sheen " of the bridge . Austrian Germanist Rudolf Simek says that Bifröst either means " the swaying road to heaven " ( also citing <unk> ) or , if Bilröst is the original form of the two ( which Simek says is likely ) , " the fleetingly glimpsed rainbow " ( possibly connected to bil , perhaps meaning " moment , weak point " ) . 
