The Collaborative International Dictionary of English v.0.48:

Inheritable \In*her"it*a*ble\, a.
   1. Capable of being inherited; transmissible or descendible;
      as, an inheritable estate or title. --Blackstone.
      [1913 Webster]

   2. Capable of being transmitted from parent to child; as,
      inheritable qualities or infirmities.
      [1913 Webster]

   3. [Cf. OF. enheritable, inheritable.] Capable of taking by
      inheritance, or of receiving by descent; capable of
      succeeding to, as an heir.
      [1913 Webster]

            By attainder . . . the blood of the person attainted
            is so corrupted as to be rendered no longer
            inheritable.                          --Blackstone.
      [1913 Webster]

            The eldest daughter of the king is also alone
            inheritable to the crown on failure of issue male.
                                                  --Blackstone.
      [1913 Webster]

   Inheritable blood, blood or relationship by which a person
      becomes qualified to be an heir, or to transmit
      possessions by inheritance.
      [1913 Webster]

WordNet (r) 3.0 (2006):

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