book end

noun

one of a pair of usually ornamental supports for holding a row of books upright

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Examples from the Web for book-end

Contemporary Examples of book-end

The book-end nuclear threats from North Korea and Iran come first to mind.
Obama's Next Six Crises
Leslie H. Gelb
September 11, 2009