The Collaborative International Dictionary of English v.0.48:

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.
   [1913 Webster]

WordNet (r) 3.0 (2006):

grapeshot
    n 1: a cluster of small projectiles fired together from a cannon
         to produce a hail of shot [syn: grapeshot, grape]

Moby Thesaurus II by Grady Ward, 1.0:

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



The Devil's Dictionary (1881-1906):

GRAPESHOT, n.  An argument which the future is preparing in answer to
the demands of American Socialism.