1. [n]  the act of branching out or dividing into branches
2. [n]  cutlery used for serving and eating food
3. [n]  an agricultural tool used for lifting or digging; has a handle and metal prongs
4. [n]  the angle formed by the inner sides of the legs where they join the human trunk
5. [n]  a part of a forked or branching shape; "he broke off one of the branches"; "they took the south fork"
6. [v]  shape like a fork; "She forked her fingers"
7. [v]  divide into two or more branches so as to form a fork; "The road forks"
8. [v]  place under attack with one's own pieces, of two enemy chess pieces
9. [v]  lift with a pitchfork; "pitchfork hay"

1. \Fork\ (f[^o]rj), n. [AS. forc, fr. L. furca. Cf.
   {Fourch['e]}, {Furcate}.]
   1. An instrument consisting of a handle with a shank
      terminating in two or more prongs or tines, which are
      usually of metal, parallel and slightly curved; -- used
      from piercing, holding, taking up, or pitching anything.
   2. Anything furcate or like a fork in shape, or furcate at
      the extremity; as, a tuning fork.
   3. One of the parts into which anything is furcated or
      divided; a prong; a branch of a stream, a road, etc.; a
      barbed point, as of an arrow.
            Let it fall . . . though the fork invade The region
            of my heart.                          --Shak.
            A thunderbolt with three forks.       --Addison.
   4. The place where a division or a union occurs; the angle or
      opening between two branches or limbs; as, the fork of a
      river, a tree, or a road.
   5. The gibbet. [Obs.] --Bp. Butler.
   {Fork beam} (Shipbuilding), a half beam to support a deck,
      where hatchways occur.
   {Fork chuck} (Wood Turning), a lathe center having two prongs
      for driving the work.
   {Fork head}.
      (a) The barbed head of an arrow.
      (b) The forked end of a rod which forms part of a knuckle
          joint.
   {In fork}. (Mining) A mine is said to be in fork, or an
      engine to ``have the water in fork,'' when all the water
      is drawn out of the mine. --Ure.
   {The forks of a river} or {a road}, the branches into which
      it divides, or which come together to form it; the place
      where separation or union takes place.
   

2. \Fork\, v. i. [imp. & p. p. {Forked}; p. pr. & vb. n.
   {Forking}.]
   1. To shoot into blades, as corn.
            The corn beginneth to fork.           --Mortimer.
   2. To divide into two or more branches; as, a road, a tree,
      or a stream forks.
   

3. \Fork\, v. t.
   To raise, or pitch with a fork, as hay; to dig or turn over
   with a fork, as the soil.
         Forking the sheaves on the high-laden cart. --Prof.
                                                  Wilson.
   {To fork} {over or out}, to hand or pay over, as money.
      [Slang] --G. Eliot.
   

A Unix system call used by a process (the "parent") to make a copy (the "child") of itself. The child process is identical to the parent except it has a different process identifier and a zero return value from the fork call. It is assumed to have used no resources.

A fork followed by an exec can be used to start a different process but this can be inefficient and some later Unix variants provide vfork as an alternative mechanism for this.

See also fork bomb.