Source : Webster's Revised Unabridged Dictionary (1913)

Atrocious \A*tro"cious\, a. [L. atrox, atrocis, cruel, fierce:
   cf. F. atroce.]
   1. Extremely heinous; full of enormous wickedness; as,
      atrocious quilt or deeds.

   2. Characterized by, or expressing, great atrocity.

            Revelations . . . so atrocious that nothing in
            history approaches them.              --De Quincey.

   3. Very grievous or violent; terrible; as, atrocious
      distempers. [Obs.] --Cheyne.

   Syn: {Atrocious}, {Flagitious}, {Flagrant}.

   Usage: Flagitious points to an act as grossly wicked and
          vile; as, a flagitious proposal. Flagrant marks the
          vivid impression made upon the mind by something
          strikingly wrong or erroneous; as, a flagrant
          misrepresentation; a flagrant violation of duty.
          Atrocious represents the act as springing from a
          violent and savage spirit. If Lord Chatham, instead of
          saying ``the atrocious crime of being a young man,''
          had used either of the other two words, his irony
          would have lost all its point, in his celebrated reply
          to Sir Robert Walpole, as reported by Dr. Johnson. --
          {A*tro"cious*ly}, adv. -- {A*tro"cious*ness}, n.

Source : WordNet®

atrocious
     adj 1: shockingly brutal or cruel; "murder is an atrocious crime";
            "a grievous offense against morality"; "a grievous
            crime"; "no excess was too monstrous for them to
            commit" [syn: {flagitious}, {grievous}, {heinous}, {monstrous}]
     2: exceptionally bad or displeasing; "atrocious taste";
        "abominable workmanship"; "an awful voice"; "dreadful
        manners"; "a painful performance"; "terrible handwriting";
        "an unspeakable odor came sweeping into the room" [syn: {abominable},
         {awful}, {dreadful}, {painful}, {terrible}, {unspeakable}]
     3: provoking horror; "an atrocious automobile accident"; "a
        frightful crime of decapitation"; "an alarming, even
        horrifying, picture"; "war is beyond all words horrible"-
        Winston Churchill; "an ugly wound" [syn: {frightful}, {horrifying},
         {horrible}, {ugly}]