The Collaborative International Dictionary of English v.0.48:

Freestone \Free"stone`\, n.
   A stone composed of sand or grit; -- so called because it is
   easily cut or wrought.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Freestone \Free"stone`\, a.
   Having the flesh readily separating from the stone, as in
   certain kinds of peaches.
   [1913 Webster]

WordNet (r) 3.0 (2006):

freestone
    n 1: fruit (especially peach) whose flesh does not adhere to the
         pit