Snow·ball n.
  1. A round mass of snow pressed or roller together, or anything resembling such a mass.
  2. Bot. The Guelder-rose.
  Snowball bush or Snowball tree Bot., the Guelder-rose.
  a snowball's chance in hell, [Colloq.] no chance; an infinitesimal chance.
  Guel·der·rose' n.  Bot. A cultivated variety of a species of Viburnum (V. Opulus), bearing large bunches of white flowers; -- called also snowball tree.
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