(from the Fr. bloc, and possibly connected with an Old Ger. Block, obstruction, cf. "baulk"), a piece of wood. The word is used in various senses, e.g. the block upon which people were beheaded, the block or mould upon which a hat is shaped, a pulley-block, a printing-block, &c. From the sense of a solid mass comes the expression, a "block" of houses, i.e. a rectangular space covered with houses and bounded by four streets. From the sense of "obstruction" comes a "block" in traffic, a block in any proceedings, and the block system of signalling on railways.