paper-weight

Noun

paperweight (plural paperweights)

1. A small, decorative, somewhat weighty object placed on one or more pieces of paper to keep them from fluttering away.
   • The ability of a segment of a glass sphere to magnify whatever is placed before it was known around the year 1000, when the spherical segment was called a reading stone, essentially what today we might term a frameless magnifying glass or plain glass paperweight.2013 September-October, Henry Petroski, “The Evolution of Eyeglasses”, in American Scientist
2. Any object used for this purpose.
   • John used his coffee mug as a paperweight.
3. (slang) A useless piece of equipment.
   • On Windows, the card has a working driver. On Linux right now, it's a paperweight.