slough of despond

noun phrase

slough of de·​spond ˌslau̇-əv-di-ˈspänd 

ˌslü-

: a state of extreme depression

Word History

Etymology

from the Slough of Despond, deep bog into which Christian falls on the way from the City of Destruction and from which Help saves him in the allegory Pilgrim's Progress (1678) by John Bunyan

First Known Use

1776, in the meaning defined above