book prop

book prop (plural book props)

1. A large, wooden support structure used to support an oversized book, usually found in a library.
   • 1862, Edward Bulwer Lytton Baron Lytton, A Strange Story, Volume 1, page 214:

     The arm-chair by the fireplace; the knee-hole writing-table beside it; the sofa near the recess of a large bay-window, with book-prop and candlestick screwed to its back;