Source : Webster's Revised Unabridged Dictionary (1913)

Nicker nut \Nick"er nut`\
   A rounded seed, rather smaller than a nutmeg, having a hard
   smooth shell, and a yellowish or bluish color. The seeds grow
   in the prickly pods of tropical, woody climbers of the genus
   {C[ae]salpinia}. {C. Bonduc} has yellowish seeds; {C.
   Bonducella}, bluish gray. [Spelt also {neckar nut}, {nickar
   nut}.]