The Collaborative International Dictionary of English v.0.48:

Chauvinism \Chau"vin*ism\, n. [F. chauvinisme, from Nicolas
   Chauvin, a character represented as making grotesque and
   threatening displays of his attachment to his fallen chief,
   Napoleon I., in 1815 (in the play La Cocarde tricolor,
   1831).]
   1. Blind and absurd devotion to a fallen leader or an
      obsolete cause; hence, absurdly vainglorious or
      exaggerated patriotism.
      [1913 Webster]

   2. exaggerated and unreasoning partisanship to any group or
      cause; -- as, male chauvinism, i.e. belief in the
      superiority of males.
      [PJC] -- Chau"vin*ist, n. & adj. -- Chau`vin*is"tic,
      a.
      [1913 Webster]

   Note: To have a generous belief in the greatness of one's
         country is not chauvinism. It is the character of the
         latter quality to be wildly extravagant, to be fretful
         and childish and silly, to resent a doubt as an insult,
         and to offend by its very frankness. --Prof. H. Tuttle.
         [1913 Webster]

WordNet (r) 3.0 (2006):

chauvinist
    n 1: a person with a prejudiced belief in the superiority of his
         or her own kind
    2: an extreme bellicose nationalist [syn: chauvinist,
       jingoist, jingo, flag-waver, hundred-percenter,
       patrioteer]

Moby Thesaurus II by Grady Ward, 1.0:

27 Moby Thesaurus words for "chauvinist":
   bigot, chauvin, doctrinaire, dogmatist, fanatic, flag waver,
   hard hat, hawk, hundred-percent American, hundred-percenter,
   illiberal, intolerant, jingo, jingoist, male chauvinist,
   militarist, nationalist, patriot, patrioteer, pig, racist, sexist,
   superpatriot, ultranationalist, war dog, war hawk, warmonger