Source : Webster's Revised Unabridged Dictionary (1913)

Grapeshot \Grape"shot`\, n. (Mil.)
   A cluster, usually nine in number, of small iron balls, put
   together by means of cast-iron circular plates at top and
   bottom, with two rings, and a central connecting rod, in
   order to be used as a charge for a cannon. Formerly grapeshot
   were inclosed in canvas bags.

Source : WordNet®

grapeshot
     n : a cluster of small projectiles fired together from a cannon
         to produce a hail of shot