Source : Webster's Revised Unabridged Dictionary (1913)

Obstinacy \Ob"sti*na*cy\, n. [See {Obstinate}.]
   1. A fixedness in will, opinion, or resolution that can not
      be shaken at all, or only with great difficulty; firm and
      usually unreasonable adherence to an opinion, purpose, or
      system; unyielding disposition; stubborness; pertinacity;
      persistency; contumacy.

            You do not well in obstinacy To cavil in the course
            of this contract.                     --Shak.

            To shelter their ignorance, or obstinacy, under the
            obscurity of their terms.             --Locke.

   2. The quality or state of being difficult to remedy,
      relieve, or subdue; as, the obstinacy of a disease or
      evil.

   Syn: Pertinacity; firmness; resoluteness; inflexibility;
        persistency; stubbornness; perverseness; contumacy.

   Usage: {Obstinacy}, {Pertinacity}. Pertinacity denotes great
          firmness in holding to a thing, aim, etc. Obstinacy is
          great firmness in holding out against persuasion,
          attack, etc. The former consists in adherence, the
          latter in resistance. An opinion is advocated with
          pertinacity or defended with obstinacy. Pertinacity is
          often used in a good sense; obstinacy generally in a
          bad one. ``In this reply was included a very gross
          mistake, and if with pertinacity maintained, a capital
          error.'' --Sir T. Browne. ``Every degree of obstinacy
          in youth is one step to rebellion.'' --South.

Source : WordNet®

obstinacy
     n 1: the trait of being difficult to handle or overcome [syn: {stubbornness},
           {obstinance}, {mulishness}]
     2: resolute adherence to your own ideas or desires [syn: {stubbornness},
         {bullheadedness}, {obstinance}, {pigheadedness}, {self-will}]