The Collaborative International Dictionary of English v.0.48:

Forfeitable \For"feit*a*ble\, a.
   Liable to be forfeited; subject to forfeiture.
   [1913 Webster]

         For the future, uses shall be subject to the statutes
         of mortmain, and forfeitable, like the lands
         themselves.                              --Blackstone.
   [1913 Webster]