a piece of wood more or less bulky; a solid mass of wood, stone, etc., usually with one or more plane, or approximately plane, faces; as, a block on which a butcher chops his meat; a block by which to mount a horse; children's playing blocks, etc.-the solid piece of wood on which condemned persons lay their necks when they are beheaded.-the wooden mold on which hats, bonnets, etc., are shaped.-the pattern or shape of a hat.-a large or long building divided into separate houses or shops, or a number of houses or shops built in contact with each other so as to form one building; a row of houses or shops.-a square, or portion of a city inclosed by streets, whether occupied by buildings or not.-a grooved pulley or sheave incased in a frame or shell which is provided with a hook, eye, or strap, by which it may be attached to an object. it is used to change the direction of motion, as in raising a heavy object that can not be conveniently reached, and also, when two or more such sheaves are compounded, to change the rate of motion, or to exert increased force; -- used especially in the rigging of ships, and in tackles.-the perch on which a bird of prey is kept.-any obstruction, or cause of obstruction; a stop; a hindrance; an obstacle; as, a block in the way.-a piece of box or other wood for engravers' work.-a piece of hard wood (as mahogany or cherry) on which a stereotype or electrotype plate is mounted to make it type high.-a blockhead; a stupid fellow; a dolt.-a section of a railroad where the block system is used. see block system, below.-to obstruct so as to prevent passage or progress; to prevent passage from, through, or into, by obstructing the way; -- used both of persons and things; -- often followed by up; as, to block up a road or harbor.-to secure or support by means of blocks; to secure, as two boards at their angles of intersection, by pieces of wood glued to each.-to shape on, or stamp with, a block; as, to block a hat.