Adverb
somewhere over the rainbow (not comparable)
(idiomatic) at an unknown, hypothetical, or very distant place
Before we had airplanes and astronauts, we really thought that there was an actual place beyond the clouds, somewhere over the rainbow. There was an actual place, and we could go above the clouds and find it.there. Barbara Walters
My mother had a lot of parties when I was a child. There'd always be a moment when she would place me on the upright piano and have me sing Somewhere Over the Rainbow. Rufus Wainwright