<p><strong>Noun</strong></p><ul><li>a solid mass of wood, stone, etc., usually with one or more flat or approximately flat faces.</li><li>a hollow masonry building unit of cement, terracotta, etc.: a wall made of concrete blocks.</li><li>one of a set of cube-shaped pieces of wood, plastic, or the like, used as a child's toy in building.</li><li>a mold or piece on which something is shaped or kept in shape: a hat block.</li><li>a piece of wood used in the art of making woodcuts or wood engravings.</li><li>Printing: the base on which a plate is mounted to make it type-high.</li><li>a projection left on a squared stone to provide a means of lifting it.</li><li>a short length of plank serving as a bridging, as between joists.</li><li>a stump or wooden structure on which a condemned person is beheaded: Mary Stuart went bravely to the block.</li><li>auction block.</li><li>Machinery: a part enclosing one or more freely rotating, grooved pulleys, about which ropes or chains pass to form a hoisting or hauling tackle.</li><li>an obstacle, obstruction, or hindrance: His stubbornness is a block to all my efforts.</li><li>Synonyms: jam, stoppage, barrier, blockade, impediment.</li><li>the state or condition of being obstructed; blockage: The traffic block lasted several hours.</li><li>Pathology: an obstruction, as of a nerve.</li><li>heart block.</li><li>Sports: a hindering of an opponent's actions.</li><li>a quantity, portion, or section taken as a unit or dealt with at one time: a large block of theater tickets.</li><li>a small section of a city, town, etc., enclosed by neighboring and intersecting streets: She lives on my block.</li><li>the length of one side of such a section: We walked two blocks over.</li><li>Chiefly British: a large building divided into separate apartments, offices, shops, etc.</li><li>a large number of bonds or shares of stock sold together as a single unit.</li><li>Computers: a group of data stored as a unit on an external storage medium and handled as a unit by the computer for input or output: This file has 20 records per block.</li><li>a section of storage locations in a computer allocated to a particular set of instructions or data.</li><li>a group of consecutive machine words organized as a unit and guiding a particular computer operation, especially with reference to input and output.</li><li>(on a flow chart) a symbol representing an operation, device, or instruction in a computer program.</li><li>Railroads: any of the short lengths into which a track is divided for signaling purposes.</li><li>Philately: a group of four or more unseparated stamps, not in a strip.</li><li>Slang: a person's head.</li><li>Glassmaking: a wooden or metal cup for blocking a gather.</li><li>an obstruction or stoppage in mental processes or speech, especially when related to stress, emotional conflict, etc.</li><li>writer's block.</li><li>Geology: any large, angular mass of solid rock.</li><li>fault block.</li><li>(in Canada) a wild or remote area of land that has not yet been surveyed: the Peace River block.</li><li>Automotive: cylinder block.</li><li>Falconry: a low perch to which a falcon is tethered outdoors.</li></ul><p><strong>Verb</strong></p><ul><li>(used with object) to obstruct (someone or something) by placing obstacles in the way (sometimes followed by up): to block one's exit; to block up a passage.</li><li>Synonyms: stop, deter, hinder, impede, blockade, close.</li><li>to fit with blocks; mount on a block.</li><li>to shape or prepare on or with a block: to block a hat; to block a sweater.</li><li>to join (the ends of boards or the like) by fastening to a block of wood.</li><li>Theater: Also block out. to plan or work out the movement of performers in a play, pageant, etc.: Tomorrow we'll block act one.</li><li>to draw a floor plan on (a stage) in order to indicate placement of scenery, stage property, etc.</li><li>Pathology, Physiology: to stop the passage of impulses in (a nerve).</li><li>Computers: to group (contiguous data) together so as to allow to be read or written in a single operation.</li><li>Sports: to hinder or bar the actions or movements of (an opposing player), especially legitimately.</li><li>Glassmaking: to shape (a molten gather) in a wet cup of wood or metal.</li><li>to plunge a block of wood into (molten glass) to aid in refining the glass.</li><li>Metalworking: to give (a forging) a rough form before finishing.</li><li>Electronics: to apply a high negative bias to the grid of (a vacuum tube), for reducing the plate current to zero.</li><li>(used without object) to act so as to obstruct an opponent, as in football, hockey, and basketball: He doesn't get many baskets, but he sure can block.</li><li>Theater: to block a play, act, scene, stage, etc.: The director will block tomorrow.</li><li>to suffer a block.</li><li>verb phrase block (def 36a).</li><li>Basketball: to box out.</li><li>to sketch or outline roughly or generally, without details: She blocked out a color scheme for the interiors.</li></ul>