Please answer before reading others’ responses. And include, if you will, from where in the world you learned what it is. No dictionaries allowed! This word seems to have different meanings in different places.
My definition and place:
Slough: A side channel to a river, under the influence of tide waters. Place: southern Oregon coast, USA.
I thought it was a city in England. I live in Arizona, USA and I think I learned the word from a list of cities which a former company I worked for had an office.
I learned it from my Canadian* grandfather as a body of water. Not entirely clear what kind: I think of it as still water, like a temporary pond or lake. Slough “sluff” is the snake thing, “slew” is the water. ETA: Almost exactly what Gorsnak said, and I didn’t even see his (her?) comment on preview.
We have many around here including Munson Slough, but none of them are “under the influence of tide waters”. Most are side waters off rivers (too far up for tide to be an issue) or lakes.
I had a vague idea it was a marshy area, but that’s from reading the Laura Ingalls Wilder books, um, many years ago. Never heard it outside that context. Midwest, US.
I’ve heard it to mean peel off and fall away, such as a snake sloughing its skin. I think I’ve heard it to mean slacking off or being lazy. And lastly, I seem to remember it being used in Pilgrim’s Progress, via Little Women, as “the Slough of Despond”, which always made me think of a swampy area with mud so thick you can get stuck and sink in it.
Other than the last, I don’t recall where else I’ve heard the word.
If it rhymed with plough, I would’ve gone with the town. In fact, that’s how I thought it was always pronounced , I’ve only seen it written (not a native English speaker).
I thought it meant a valley. I seem to recall a slough of despair or something in Pilgrim’s Progress. I’ve heard of the British city also. A company I worked for in the eighties had a development center there.