The Collaborative International Dictionary of English v.0.48:

nationalistic \nationalistic\ adj.
   1. Fanatically patriotic; chauvinistic.

   Syn: chauvinistic, flag-waving(prenominal), jingoistic,
        superpatriotic.
        [WordNet 1.5]

   2. Devotion to the interests or culture of a particular
      nation including promoting the interests of one country
      over those of others; as, minor nationalistic differences.

   Syn: nationalist.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

nationalistic
    adj 1: fanatically patriotic [syn: chauvinistic, flag-
           waving(a), jingoistic, nationalistic,
           ultranationalistic, superpatriotic]
    2: devotion to the interests or culture of a particular nation
       including promoting the interests of one country over those
       of others; "nationalist aspirations"; "minor nationalistic
       differences" [syn: nationalist, nationalistic]