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

Moby Thesaurus II by Grady Ward, 1.0:

23 Moby Thesaurus words for "shrapnel":
   ball, bar shot, bird shot, buckshot, bullet, cannon shot,
   cannonball, case shot, crossbar shot, duck shot, dumdum bullet,
   expanding bullet, grape, grapeshot, langrel shot,
   manstopping bullet, pellet, rifle ball, round shot, shell, shot,
   slug, split shot