The Collaborative International Dictionary of English v.0.48:

Heritable \Her"it*a*ble\, a. [OF. h['e]ritable. See Heritage,
   Hereditable.]
   1. Capable of being inherited or of passing by inheritance;
      inheritable.
      [1913 Webster]

   2. Capable of inheriting or receiving by inheritance.
      [1913 Webster]

            This son shall be legitimate and heritable. --Sir M.
                                                  Hale.
      [1913 Webster]

   Heritable rights (Scots Law), rights of the heir; rights to
      land or whatever may be intimately connected with land;
      realty. --Jacob (Law Dict.).
      [1913 Webster]

WordNet (r) 3.0 (2006):

heritable
    adj 1: capable of being inherited; "inheritable traits such as
           eye color"; "an inheritable title" [syn: inheritable,
           heritable] [ant: nonheritable, noninheritable]