1. A large block of stone, especially one used in architecture or sculpture.

2. Something, such as a column or monument, made from one large block of stone.

3. An outcropping, cliff, or mountain having the appearance of a single block of stone: "On a waterway of grand pilot marks, the finest lay just ahead, Beacon Rock, a distinctive black monolith some eight hundred feet high" (William Least Heat-Moon).

4. Something suggestive of a large block of stone, as in immovability, massiveness, or uniformity: "Standing against a global Communism it took to be monolithic, the Pentagon wanted to be taken as a monolith" (William Carroll).