The Collaborative International Dictionary of English v.0.48:

Kentucky \Ken*tuck"y\, prop. n.
   One of the United States.
   [1913 Webster]

   Kentucky blue grass (Bot.), a valuable pasture and meadow
      grass (Poa pratensis), found in both Europe and America.
      See under Blue grass.

   Kentucky coffee tree (Bot.), a tall North American tree
      (Gymnocladus Canadensis) with bipinnate leaves. It
      produces large woody pods containing a few seeds which
      have been used as a substitute for coffee. The timber is
      very valuable.
      [1913 Webster]

WordNet (r) 3.0 (2006):

Kentucky coffee tree
    n 1: handsome tree of central and eastern North America having
         large bipinnate leaves and green-white flowers followed by
         large woody brown pods whose seeds are used as a coffee
         substitute [syn: Kentucky coffee tree, bonduc,
         chicot, Gymnocladus dioica]