WordWeb Online

1. Stubbornly unyielding
   "dour determination";
   - dogged, persistent, pertinacious, tenacious, unyielding
    
2. Harshly uninviting or formidable in manner or appearance
   "a dour, self-sacrificing life";
   - forbidding, grim
    
3. Showing a brooding ill humour
   "the proverbially dour New England Puritan";
   - dark, glowering, glum, moody, morose, saturnine, sour, sullen

Derived forms: dourer, dourest

See also: ill-natured, obstinate, stubborn, unpleasant, unregenerate

Encyclopedia: Dour