Source : Webster's Revised Unabridged Dictionary (1913)

Doctrinaire \Doc`tri*naire"\, n. [F. See {Doctrine}.]
   One who would apply to political or other practical concerns
   the abstract doctrines or the theories of his own
   philosophical system; a propounder of a new set of opinions;
   a dogmatic theorist. Used also adjectively; as, doctrinaire
   notions.

   Note: In french history, the Doctrinaires were a
         constitutionalist party which originated after the
         restoration of the Bourbons, and represented the
         interests of liberalism and progress. After the
         Revolution of July, 1830, when they came into power,
         they assumed a conservative position in antagonism with
         the republicans and radicals. --Am. Cyc.

Source : WordNet®

doctrinaire
     adj : stubbornly insistent on theory without regard for
           practicality or suitability
     n : a stubborn person of arbitrary or arrogant opinions [syn: {dogmatist}]