after fell from the everest(crest).u felt sad and disappointed.
crest +fallen; after winning the game he got a CREST but after few moments it was FALLEN and hence he was very DISAPPOINTED.
crest+fallen.....crest means top part of hill ....or wave......now people who always remain on top..when don't perform they feel despirited
crestfallen...take fallen, when u fail or fall in something important, u feel dejected
some one with such bad haalat as if he has falllen from a high cliff down to the ground below