Source : Webster's Revised Unabridged Dictionary (1913)

Grisly \Gris"ly\, a. [OE, grisly, grislich, AS. grislic,
   gryslic, fr. gr?san to shudder; cf. OD. grijselick horrible,
   OHG. grisenl?ch, and also AS. gre?san to frighten, and E.
   gruesome.]
   Frightful; horrible; dreadful; harsh; as, grisly locks; a
   grisly specter. ``Grisly to behold.'' --Chaucer.

         A man of grisly and stern gravity.       --Robynson
                                                  (More's
                                                  Utopia).

   {Grisly bear}. (Zo["o]l.) See under {Grizzly}.

Source : WordNet®

grisly
     adj : shockingly repellent; inspiring horror; "ghastly wounds";
           "the grim aftermath of the bombing"; "the grim task of
           burying the victims"; "a grisly murder"; "gruesome
           evidence of human sacrifice"; "macabre tales of war and
           plague in the Middle ages"; "macabre tortures conceived
           by madmen" [syn: {ghastly}, {grim}, {gruesome}, {macabre}]
     [also: {grisliest}, {grislier}]