Block  —n. 1 solid piece of hard material, esp. Stone or wood. 2 this as a base for chopping etc., as a stand, or for mounting a horse from. 3 a large building, esp. When subdivided. B group of buildings between streets. 4 obstruction. 5 two or more pulleys mounted in a case. 6 piece of wood or metal engraved for printing. 7 slang head. 8 (often attrib.) Number of things as a unit, e.g. Shares, theatre seats (block booking). 9 sheets of paper glued along one edge. —v. 1 a (often foll. By up) obstruct. B impede. 2 restrict the use of. 3 cricket stop (a ball) with a bat defensively.  block in 1 sketch roughly; plan. 2 confine. Block out 1 shut out (light, noise, a memory, view, etc.). 2 sketch roughly; plan. Block up confine; enclose. [low german or dutch]