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 Cæsalpinia. C. Bonduc has yellowish seeds; C. Bonducella, bluish gray. [Spelt also neckar nut, nickar nut.]