Source : Webster's Revised Unabridged Dictionary (1913)

Cobnut \Cob"nut`\, n.
   1. (Com.) A large roundish variety of the cultivated
      hazelnut.

   2. A game played by children with nuts.

Source : WordNet®

cobnut
     n 1: small nut-bearing tree much grown in Europe [syn: {filbert},
           {Corylus avellana}, {Corylus avellana grandis}]
     2: nut of any of several trees of the genus Corylus [syn: {hazelnut},
         {filbert}, {cob}]