The Collaborative International Dictionary of English v.0.48:

Gymnocarpous \Gym`no*car"pous\ (j[i^]m`n[-o]*k[aum]r"p[u^]s), a.
   [Gr. gymno`s naked + karpo`s fruit.] (Bot.)
   Naked-fruited, the fruit either smooth or not adherent to the
   perianth. --Gray.
   [1913 Webster]