dour in WordNet English dictionary

1. showing a brooding ill humor
   "a dark scowl"; "the proverbially dour New England Puritan"; "a glum, hopeless shrug"; "he sat in moody silence"; "a morose and unsociable manner"; "a saturnine, almost misanthropic young genius"- Bruce Bliven; "a sour temper"; "a sullen crowd"
   dark  dour  glowering  glum  moody  morose  saturnine  sour  sullen 
   
2. stubbornly unyielding
   "dogged persistence"; "dour determination"; "the most vocal and pertinacious of all the critics"; "a mind not gifted to discover truth but tenacious to hold it"- T.S.Eliot; "men tenacious of opinion"
   dogged  dour  persistent  pertinacious  tenacious  unyielding 
   
3. harshly uninviting or formidable in manner or appearance
   "a dour, self-sacrificing life"; "a forbidding scowl"; "a grim man loving duty more than humanity"; "undoubtedly the grimmest part of him was his iron claw"- J.M.Barrie
   dour  forbidding  grim