Slough of Des ‧ pond, the /ˌslaʊ əv dɪˈspɒnd $ ˌsluː əv dɪˈspɑːnd, ˌslaʊ-/ BrE AmE literary
a situation in which you are very unhappy and there seems to be no hope that things will improve, from the name of a place in the book The Pilgrim's Progress by John ↑ Bunyan