Merriam-Webster Collegiate Dictionary - cacao

 noun  (plural ~s)  Etymology: Spanish, from Nahuatl cacahuatl  Date: 1555  1. the dried partly fermented fatty seeds of a South American evergreen tree (Theobroma ~ of the family Sterculiaceae) that are used in making cocoa, chocolate, and cocoa butter — called also ~ bean, cocoa bean  2. a tree having small yellowish flowers followed by fleshy pods from which ~ is obtained