Other forms: creeks
A creek is a stream — like a river, but smaller — and if you grew up in the TV version of rural America, you probably had a creek babbling through your backyard and a dog that looked like Lassie.
If you're "up a creek," or "up a creek without a paddle," you've got a problem with no solution in sight. Say you're out in the middle of nowhere, your cell phone battery has just died, and your car won't start. Unless you've got a solar charger or a tow truck comes along, you're definitely up a creek.