prune \prune\, n. f. prune, from l. prunum a plum. see plum.
   a plum; esp., a dried plum, used in cookery; as, french or
   turkish prunes; california prunes.
   1913 webster

   german prune bot., a large dark purple plum, of oval
      shape, often one-sided. it is much used for preserving,
      either dried or in sirup.

   prune tree. bot.
   a a tree of the genus prunus prunus domestica, which
       produces prunes.
   b the west indian tree, prunus occidentalis.

   south african prune bot., the edible fruit of a
      sapindaceous tree pappea capensis.
      1913 webster
see also:
plum german prune prune tree prunus prunus domestica prunus occidentalis 
south african prune pappea capensis