"monument consisting of a single large block of stone," 1829, from French monolithe (16c.), from Latin monolithus (adj.) "consisting of a single stone," from Greek monolithos "made of one stone," from monos "single, alone" (from PIE root *men- (4) "small, isolated") + lithos "stone" (see litho-). Transferred and figurative use in reference to a thing or person noted for indivisible unity is from 1934.