Source : Webster's Revised Unabridged Dictionary (1913)

Ugly \Ug"ly\, a. [Compar. {Uglier}; superl. {Ugliest}.] [Icel.
   uggligr fearful, dreadful; uggr fear (akin to ugga to fear) +
   -ligr (akin to E. -ly, like). ??. Cf. {Awe}.]
   1. Offensive to the sight; contrary to beauty; being of
      disagreeable or loathsome aspect; unsightly; repulsive;
      deformed.

            The ugly view of his deformed crimes. --Spenser.

            Like the toad, ugly and venomous.     --Shak.

            O, I have passed a miserable night, So full of ugly
            sights, of ghastly dreams.            --Shak.

   2. Ill-natured; crossgrained; quarrelsome; as, an ugly
      temper; to feel ugly. [Colloq. U. S.]

   3. Unpleasant; disagreeable; likely to cause trouble or loss;
      as, an ugly rumor; an ugly customer. [Colloq.]

Source : WordNet®

ugly
     adj 1: displeasing to the senses and morally revolting; "an ugly
            face"; "ugly furniture"; "war is ugly" [ant: {beautiful}]
     2: deficient in beauty; "ugly gray slums"
     3: inclined to anger or bad feelings with overtones of menace;
        "a surly waiter"; "an ugly frame of mind" [syn: {surly}]
     4: morally reprehensible; "would do something as despicable as
        murder"; "ugly crimes"; "the vile development of slavery
        appalled them" [syn: {despicable}, {vile}, {unworthy}]
     5: threatening or foreshadowing evil or tragic developments; "a
        baleful look"; "forbidding thunderclouds"; "his tone
        became menacing"; "ominous rumblings of discontent";
        "sinister storm clouds"; "a sinister smile"; "his
        threatening behavior"; "ugly black clouds"; "the situation
        became ugly" [syn: {baleful}, {forbidding}, {menacing}, {minacious},
         {minatory}, {ominous}, {sinister}, {threatening}]
     6: 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: {atrocious}, {frightful},
         {horrifying}, {horrible}]
     [also: {ugliest}, {uglier}]

uglier
     See {ugly}