The Collaborative International Dictionary of English v.0.48:

Shrapnel \Shrap"nel\, a.
   Applied as an appellation to a kind of shell invented by Gen.
   H. Shrapnel of the British army. -- n. A shrapnel shell;
   shrapnel shells, collectively.
   [1913 Webster]

   Shrapnel shell (Gunnery), a projectile for a cannon,
      consisting of a shell filled with bullets and a small
      bursting charge to scatter them at any given point while
      in flight. See the Note under Case shot.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Case shot \Case" shot`\ (Mil.)
   A collection of small projectiles, inclosed in a case or
   canister.
   [1913 Webster]

   Note: In the United States a case shot is a thin spherical or
         oblong cast-iron shell containing musket balls and a
         bursting charge, with a time fuse; -- called in Europe
         shrapnel. In Europe the term case shot is applied to
         what in the United States is called canister.
         --Wilhelm.
         [1913 Webster]

WordNet (r) 3.0 (2006):

shrapnel
    n 1: shell containing lead pellets that explodes in flight