The Collaborative International Dictionary of English v.0.48:

Hereditary \He*red"i*ta*ry\, a. [L. hereditarius, fr. hereditas
   heirship, inheritance, fr. heres heir: cf. F.
   h['e]r['e]ditaire. See Heir.]
   1. Descended, or capable of descending, from an ancestor to
      an heir at law; received or passing by inheritance, or
      that must pass by inheritance; as, an hereditary estate or
      crown.
      [1913 Webster]

   2. Transmitted, or capable of being transmitted, as a
      constitutional quality or condition from a parent to a
      child; as, hereditary pride, bravery, disease.

   Syn: Ancestral; patrimonial; inheritable.
        [1913 Webster]

WordNet (r) 3.0 (2006):

hereditary
    adj 1: occurring among members of a family usually by heredity;
           "an inherited disease"; "familial traits"; "genetically
           transmitted features" [syn: familial, genetic,
           hereditary, inherited, transmitted,
           transmissible]
    2: inherited or inheritable by established rules (usually legal
       rules) of descent; "ancestral home"; "ancestral lore";
       "hereditary monarchy"; "patrimonial estate"; "transmissible
       tradition" [syn: ancestral, hereditary, patrimonial,
       transmissible]

Moby Thesaurus II by Grady Ward, 1.0:

43 Moby Thesaurus words for "hereditary":
   ancestral, atavistic, bequeathed, bodily, born, coeval, congenital,
   connatal, connate, connatural, constitutional, genetic, genic,
   handed down, heritable, in the blood, inborn, inbred, incarnate,
   indigenous, inheritable, inherited, innate, instinctive,
   instinctual, matroclinous, native, native to, natural, natural to,
   organic, patrimonial, patroclinous, physical, plasmatic, plasmic,
   primal, protoplasmic, temperamental, traditional, transferable,
   transmissible, willed