noun:the part of a building that is entirely or partly below the ground
noun:the part of a building that is wholly or partly below ground level
Examples
worthless 'bargain-basement' products
I paid a 'bargain-basement' price.
Movie quotes
(..) - Oh, well... I took a risk and tried something new and discovered a talent that I didn't know I had. What's that underneath the stairs? That would be the basement. Dad? She's dead, isn't she? Ray? Ray! Ray! (..)