The Collaborative International Dictionary of English v.0.48:

Blur \Blur\ (bl[^u]r), v. t. [imp. & p. p. Blurred (bl[^u]rd);
   p. pr. & vb. n. Blurring.] [Prob. of same origin as blear.
   See Blear.]
   1. To render obscure by making the form or outline of
      confused and uncertain, as by soiling; to smear; to make
      indistinct and confused; as, to blur manuscript by
      handling it while damp; to blur the impression of a
      woodcut by an excess of ink.
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            But time hath nothing blurred those lines of favor
            Which then he wore.                   --Shak.
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   2. To cause imperfection of vision in; to dim; to darken.
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            Her eyes are blurred with the lightning's glare.
                                                  --J. R. Drake.
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   3. To sully; to stain; to blemish, as reputation.
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            Sarcasms may eclipse thine own,
            But can not blur my lost renown.      --Hudibras.
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   Syn: To spot; blot; disfigure; stain; sully.
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The Collaborative International Dictionary of English v.0.48:

Blur \Blur\ (bl[^u]r), n.
   1. That which obscures without effacing; a stain; a blot, as
      upon paper or other substance.
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            As for those who cleanse blurs with blotted fingers,
            they make it worse.                   --Fuller.
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   2. A dim, confused appearance; indistinctness of vision; as,
      to see things with a blur; it was all blur.
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   3. A moral stain or blot.
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            Lest she . . . will with her railing set a great
            blur on mine honesty and good name.   --Udall.
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WordNet (r) 3.0 (2006):

blur
    n 1: a hazy or indistinct representation; "it happened so fast
         it was just a blur"; "he tried to clear his head of the
         whisky fuzz" [syn: blur, fuzz]
    v 1: become glassy; lose clear vision; "Her eyes glazed over
         from lack of sleep" [syn: film over, glaze over,
         blur]
    2: to make less distinct or clear; "The haze blurs the hills"
       [ant: focus]
    3: make unclear, indistinct, or blurred; "Her remarks confused
       the debate"; "Their words obnubilate their intentions" [syn:
       confuse, blur, obscure, obnubilate]
    4: make a smudge on; soil by smudging [syn: smear, blur,
       smudge, smutch]
    5: make dim or indistinct; "The fog blurs my vision" [syn:
       blur, blear] [ant: focalise, focalize, focus,
       sharpen]
    6: become vague or indistinct; "The distinction between the two
       theories blurred" [syn: blur, dim, slur] [ant:
       focalise, focalize, focus]