Slough is a noun that refers to a swamp.
The origin of our word of the day is unknown, but it appears to be from Old English. In addition to being a synonym of swamp, slough is often used to refer to a situation characterized by lack of progress or activity. Here’s an example:
The city council seems to always be in one kind of slough or other. In the twelve years I’ve been covering them, I don’t remember ever seeing any kind of progress.