We have the Columbia river and slew here, but to me the word always means to sluff.
It’s a swamp. From the Slough of Desond in Pilgrim’s Progress. Also from a line in Treasure Island. One of the pirates comes down with malaria. Dr. Livesey, who is treating them, diagnoses it, and they have this exchange. (The pirate cut a page out a Bible to make the “Black Spot”.)
Regards,
Shodan
Without reading the thread, I know it as an open, outdoor collecting/storage place for water, usually used for watering livestock. Also known as a “dug-out” when it’s on a farm (sloughs can be natural or man-made; dug-outs are only man-made).
I’m from the Canadian prairies.
I see my prairie cred is intact! 
Ok, I didn’t read further than the OP. I pronounce it “slew,” I’m from the west coast of US.
Missed the edit window
I am thinking of a body of water, specifically, a small river.
When meaning “to shed” as in snake skin, I pronounce it sluff. I am aware British may pronounce it “sluff” for the body of water, as well. I believe my dad did (he’s no longer on this earth, so I can’t ask him), and he was from Ohio.
I’ve never heard the watery definitions, just the uninspiring town and icky peeling.
I feel the 1937 poem from Sir John Betjeman coming on:
Slough
Come friendly bombs and fall on Slough!
It isn’t fit for humans now,
There isn’t grass to graze a cow.
Swarm over, Death!
Come, bombs and blow to smithereens
Those air -conditioned, bright canteens,
Tinned fruit, tinned meat, tinned milk, tinned beans,
Tinned minds, tinned breath.
Mess up the mess they call a town-
A house for ninety-seven down
And once a week a half a crown
For twenty years.
And get that man with double chin
Who’ll always cheat and always win,
Who washes his repulsive skin
In women’s tears:
And smash his desk of polished oak
And smash his hands so used to stroke
And stop his boring dirty joke
And make him yell.
But spare the bald young clerks who add
The profits of the stinking cad;
It’s not their fault that they are mad,
They’ve tasted Hell.
It’s not their fault they do not know
The birdsong from the radio,
It’s not their fault they often go
To Maidenhead
And talk of sport and makes of cars
In various bogus-Tudor bars
And daren’t look up and see the stars
But belch instead.
In labour-saving homes, with care
Their wives frizz out peroxide hair
And dry it in synthetic air
And paint their nails.
Come, friendly bombs and fall on Slough
To get it ready for the plough.
The cabbages are coming now;
The earth exhales.
Same here.
a channel or side-channel of a larger body of water. The water should be flowing-though very slowly. Around here a pond or lake is never a slough. Deep enough to navigate in-though a pirogue counts.
First thing I thought of when I opened this thread was “it’s that thing a snake does when it gets rid of its old skin.”
It means you slew someone , but they died very sloughly.
It seems strange to hear Slough described as a “city”. I realise that the term is used slightly differently elsewhere, but Slough is the epitome of drab town-iness. Very much not a city, in our terms.
Without reading any replies, I only think of that word in conjunction with women’s periods. The process of sloughing out old tissue.
Edited to add:
Sorry, didn’t notice the pronunciation stipulation. My version is pronounced “sluff.”
“Slew” doesn’t really make me think of anything. Maybe past tense for slaying someone?
A triple crown winning horse, as in “Seattle Slough.”
Crap, your spoiler appeared when I clicked quote. But basically, yeah, a slough is a little inlet that resembles a river but isn’t one because it’s actually linked in some way to the ocean.
There’s one in my hometown. Everyone calls it a river, but I learned that it’s technically a slough when I was in high school.
Northern California, US.
Agreed, that’s how I understand it. With the additional factor that they are not necessarily a ‘wetland’ year-round. In mid summer, especially in a dry year, they may not contain any standing water.
First of all, it’s pronounced “Sl-ow” (the “ow, I’m hurt.” sound). And it’s the place where Werndham Hogg had its branch.
And I didn’t realize i didn’t know how to spell Werndham Hogg until I just typed it.
Mosquito hatcheries. Pronounced “slew.” Gazillions of smallish water-filled ponds, which are holes left behind by the melting of glaciers (or so I heard), strewn over what is now the Canadian prairies. Farmers are supposed to leave a fringe of plants around the edge to catch snow and keep up the water table (which is something else I heard). Not sure how much of this is true.
I also know it as “sluff” as in sloughing off skin. But ponds for mosquitoes are the first thing that pop to mind.
Grew up in Saskatchewan.
Wet marshy area. From being an Alaskan and hearing the fishing/hunting/snowmachining types carry on about being stuck in Big Slough. (somewhere near Wasilla I think,** chefguy** can confirm, I don’t fish. :D). Whoops, forgot to add, I’ve only heard it pronounced as “slew”.
Also good for tobogganing and skating in winter (the tobogganing because they’re often the only place around with even a hint of a slope. 