definition of monolith
monolith (plural monoliths) 1  A large single block of stone, used in architecture and sculpture. 2012 January 1, Henry Petroski, âThe Washington Monumentâ, in American Scientist, volume 100, number 1, page 16: The Washington Monument is often described as an obelisk, and sometimes even as a âtrue obelisk,â even though it is not.