\Rub"ble\, n. [From an assumed Old French dim. of robe
See {Rubbish}.]
1. Water-worn or rough broken stones; broken bricks, etc.,
   used in coarse masonry, or to fill up between the facing
   courses of walls.
         Inside [the wall] there was rubble or mortar.
                                               --Jowett
                                               (Thucyd.).
2. Rough stone as it comes from the quarry; also, a
   quarryman's term for the upper fragmentary and decomposed
   portion of a mass of stone; brash. --Brande & C.
3. (Geol.) A mass or stratum of fragments or rock lying under
   the alluvium, and derived from the neighboring rock.
   --Lyell.
4. pl. The whole of the bran of wheat before it is sorted
   into pollard, bran, etc. [Prov. Eng.] --Simmonds.
{Coursed rubble}, rubble masonry in which courses are formed
   by leveling off the work at certain heights.