[syn: asperity, grimness, hardship, rigor, rigour, severity, severeness, rigorousness, rigourousness]
The Collaborative International Dictionary of English v.0.48:
Grimness \Grim"ness\, n. [AS. grimnes.]
   Fierceness of look; sternness; crabbedness; forbiddingness.
   [1913 Webster]
WordNet (r) 3.0 (2006):
grimness
    n 1: the quality of being ghastly [syn: ghastliness,
         grimness, gruesomeness, luridness]
    2: something hard to endure; "the asperity of northern winters"
       [syn: asperity, grimness, hardship, rigor, rigour,
       severity, severeness, rigorousness, rigourousness]