Source : Webster's Revised Unabridged Dictionary (1913)

Soften \Sof"ten\, v. t. [imp. & p. p. {Softened}; p. pr. & vb.
   n. {Softening}.]
   To make soft or more soft. Specifically:
   (a) To render less hard; -- said of matter.

             Their arrow's point they soften in the flame.
                                                  --Gay.
   (b) To mollify; to make less fierce or intractable.

             Diffidence conciliates the proud, and softens the
             severe.                              --Rambler.
   (c) To palliate; to represent as less enormous; as, to soften
       a fault.
   (d) To compose; to mitigate; to assuage.

             Music can soften pain to ease.       --Pope.
   (e) To make calm and placid.

             All that cheers or softens life.     --Pope.
   (f) To make less harsh, less rude, less offensive, or less
       violent, or to render of an opposite quality.

             He bore his great commision in his look, But
             tempered awe, and softened all he spoke. --Dryden.
   (g) To make less glaring; to tone down; as, to soften the
       coloring of a picture.
   (h) To make tender; to make effeminate; to enervate; as,
       troops softened by luxury.

Source : WordNet®

softened
     adj 1: toned down
     2: being or made softer or less loud or clear; "the dull boom
        of distant breaking waves"; "muffled drums"; "the muffled
        noises of the street"; "muted trumpets" [syn: {dull}, {muffled},
         {muted}]
     3: (of light) not bright or glaring; "a softer diffused
        radiance" [syn: {diffused}]