1. [n]  the act of blocking someone's path with your body (as in football); "he threw a rolling block into the line backer"
2. [n]  a platform from which an auctioneer sells; "they put their paintings on the block"
3. [n]  a solid piece of something (usually having flat rectangular sides); "the pyramids were built with large stone blocks"
4. [n]  housing in a large building that is divided into separate units; "there is a block of classrooms in the west wing"
5. [n]  an obstruction in a pipe or tube; "we had to call a plumber to clear out the blockage in the drainpipe"
6. [n]  a metal casting containing the cylinders and cooling ducts of an engine; "the engine had to be replaced because the block was cracked"
7. [n]  a simple machine consisting of a wheel with a groove in which a rope can run to change the direction or point of application of a force applied to the rope
8. [n]  an inability to remember or think of something you normally can do; often caused by emotional tension; "I knew his name perfectly well but I had a temporary block"
9. [n]  a rectangular area in a city surrounded by streets and usually containing several buildings; "he lives in the next block"
10. [n]  a number or quantity of related things dealt with as a unit; "he reserved a large block of seats"; "he held a large block of the company's stock"
11. [n]  (computer science) a sector or group of sectors that function as the smallest data unit permitted; "since blocks are often defined as a single sector, the terms `block' and `sector' are sometimes used interchangeably"
12. [n]  a three-dimensional shape with six square or rectangular sides
13. [v]  impede the movement of (an opponent or a ball), as in sports or fights; "block an attack"
14. [v]  prohibit the conversion or use of (assets); "Blocked funds"; "Freeze the assets of this hostile government"
15. [v]  shape into a block or blocks; "block the graphs so one can see the results clearly"
16. [v]  shape by using a block; "Block a hat"; "block a garment"
17. [v]  be unable to remember; "I'm drawing a blank"; "You are blocking the name of your first wife!"
18. [v]  interfere with or prevent the reception of signals; "Jam the Voice of America"; "block the signals emitted by this station"
19. [v]  support, secure, or raise with a block; "block a plate for printing"; "block the wheels of a car"
20. [v]  block passage through; "obstruct the path"
21. [v]  render unsuitable for passage; "block the way"; "barricade the streets"
22. [v]  obstruct, as of a passage; "My nose is all stuffed"; "Her arteries are blocked"
23. [v]  stamp or emboss a title or design on a book with a block; "block the book cover"
24. [v]  shut out from view; "The thick curtain blocked the action on the stage"
25. [v]  interrupt the normal function of by means of anesthesia; "block a nerve"; "block a muscle"
26. [v]  run on a block system; "block trains"
27. [v]  hinder or prevent the progress or accomplishment of; "His brother blocked him at every turn"
28. [v]  stop from happening or developing; "Block his election"; "Halt the process"

1. \Block\, n. [OE. blok; cf. F. bloc (fr. OHG.), D. & Dan.
   blok, Sw. & G. block, OHG. bloch. There is also an OHG.
   bloch, biloh; bi by + the same root as that of E. lock. Cf.
   {Block}, v. t., {Blockade}, and see {Lock}.]
   1. 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.
            Now all our neighbors' chimneys smoke, And Christmas
            blocks are burning.                   --Wither.
            All her labor was but as a block Left in the quarry.
                                                  --Tennyson.
   2. The solid piece of wood on which condemned persons lay
      their necks when they are beheaded.
            Noble heads which have been brought to the block.
                                                  --E. Everett.
   3. The wooden mold on which hats, bonnets, etc., are shaped.
      Hence: The pattern or shape of a hat.
            He wears his faith but as the fashion of his hat; it
            ever changes with the next block.     --Shak.
   4. 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.
   5. A square, or portion of a city inclosed by streets,
      whether occupied by buildings or not.
            The new city was laid out in rectangular blocks,
            each block containing thirty building lots. Such an
            average block, comprising 282 houses and covering
            nine acres of ground, exists in Oxford Street.
                                                  --Lond. Quart.
                                                  Rev.
   6. 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.
   7. (Falconry) The perch on which a bird of prey is kept.
   8. Any obstruction, or cause of obstruction; a stop; a
      hindrance; an obstacle; as, a block in the way.
   9. A piece of box or other wood for engravers' work.
   10. (Print.) A piece of hard wood (as mahogany or cherry) on
       which a stereotype or electrotype plate is mounted to
       make it type high.
   11. A blockhead; a stupid fellow; a dolt. [Obs.]
             What a block art thou !              --Shak.
   12. A section of a railroad where the block system is used.
       See {Block system}, below.
   {A block of shares} (Stock Exchange), a large number of
      shares in a stock company, sold in a lump. --Bartlett.
   {Block printing}.
       (a) A mode of printing (common in China and Japan) from
           engraved boards by means of a sheet of paper laid on
           the linked surface and rubbed with a brush. --S. W.
           Williams.
       (b) A method of printing cotton cloth and paper hangings
           with colors, by pressing them upon an engraved
           surface coated with coloring matter.
   {Block system} on railways, a system by which the track is
      divided into sections of three or four miles, and trains
      are so run by the guidance of electric signals that no
      train enters a section or block before the preceding train
      has left it.
   

2. \Block\, v. t. [imp. & p. p. {Blocked}; p. pr. & vb. n.
   {Blocking}.] [Cf. F. bloquer, fr. bloc block. See {Block},
   n.]
   1. 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.
            With moles . . . would block the port. --Rowe.
            A city . . . besieged and blocked about. --Milton.
   2. 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.
   3. To shape on, or stamp with, a block; as, to block a hat.
   {To block out}, to begin to reduce to shape; to mark out
      roughly; to lay out; as, to block out a plan.
   

3. \Block\, n.
   1. In Australia, one of the large lots into which public
      land, when opened to settlers, is divided by the
      government surveyors.
   2. (Cricket)
      (a) The position of a player or bat when guarding the
          wicket.
      (b) A block hole.
      (c) The popping crease. [R.]
   {Back blocks}, Australian pastoral country which is remote
      from the seacoast or from a river.
   

1. A unit of data or memory, often, but not exclusively, on a magnetic disk or magnetic tape.

Compare record, sector.

2. To delay or sit idle while waiting for something.

Compare busy-wait.