Source : Webster's Revised Unabridged Dictionary (1913)

Patriarchal \Pa`tri*ar"chal\, a. [Cf. F. patriarcal.]
   1. Of or pertaining to a patriarch or to patriarchs;
      possessed by, or subject to, patriarchs; as, patriarchal
      authority or jurisdiction; a patriarchal see; a
      patriarchal church.

   2. Characteristic of a patriarch; venerable.

            About whose patriarchal knee Late the little
            children clung.                       --Tennyson.

   3. (Ethnol.) Having an organization of society and government
      in which the head of the family exercises authority over
      all its generations.

   {Patriarchal cross} (Her.), a cross, the shaft of which is
      intersected by two transverse beams, the upper one being
      the smaller. See Illust. (2) of {Cross}.

   {Patriarchal dispensation}, the divine dispensation under
      which the patriarchs lived before the law given by Moses.

Source : WordNet®

patriarchal
     adj : characteristic of a patriarchy [ant: {matriarchal}]