Source : Webster's Revised Unabridged Dictionary (1913)

Garish \Gar"ish\, a. [Cf. OE. gauren to stare; of uncertain
   origin. Cf. {gairish}.]
   1. Showy; dazzling; ostentatious; attracting or exciting
      attention. ``The garish sun.'' ``A garish flag.'' --Shak.
      ``In . . . garish colors.'' --Asham. ``The garish day.''
      --J. H. Newman.

            Garish like the laughters of drunkenness. --Jer.
                                                  Taylor.

   2. Gay to extravagance; flighty.

            It makes the mind loose and garish.   --South.
      -- {Gar"ish*ly}, adv. -- {Garish*ness}, n. --Jer. Taylor.

Source : WordNet®

garishness
     n 1: tasteless showiness [syn: {flashiness}, {gaudiness}, {loudness},
           {brashness}, {meretriciousness}, {tawdriness}, {glitz}]
     2: strident color or excessive ornamentation [syn: {gaudiness}]