A moving sidewalk
I'm gonna ride the slidewalk in the airport instead of walking.
A sidewalk that is covered with ice and makes you slide when you take a step. Slide + sidewalk = slidewalk.
After the ice storm, I slipped down the slidewalk to get in my car.
A normal sidewalk that has become covered by a layer of ice, causing it to become nearly impossible to walk on. Slidewalks often result in embarassing and painful tumbles for joggers, dogwalkers, and anyone else willing to brave the below-freezing temperatures to get from point A to point B.
Sarah regretted going for a run outside when the slidewalk she was on became too slippery to run on and she fell on her ass.
A sidewalk that is covered with ice and makes you slide when you take a step. A slippery sidewalk.
After the ice storm, I took a walk on the slidewalk to get in my car.