Scratch And Dent. It means it's not perfect, but it's almost perfect.
Let's be clear: you're not getting a vacuum we dragged out of a swamp. You're getting a "scratch and dent" vacuum, which is a thing that isn't perfect, but isn't rebuilt or refurbished either. It's a vacuum that has some cosmetic issues and can't be sold as new, but kinda sorta is. And since your vacuum is going to be down there in the dirt anyway... maybe that's okay?