The Collaborative International Dictionary of English v.0.48:

Blot \Blot\, v. i.
   To take a blot; as, this paper blots easily.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Blot \Blot\, n. [Cf. Icel. blettr, Dan. plet.]
   1. A spot or stain, as of ink on paper; a blur. "Inky blots
      and rotten parchment bonds." --Shak.
      [1913 Webster]

   2. An obliteration of something written or printed; an
      erasure. --Dryden.
      [1913 Webster]

   3. A spot on reputation; a stain; a disgrace; a reproach; a
      blemish.
      [1913 Webster]

            This deadly blot in thy digressing son. --Shak.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Blot \Blot\, v. t. [imp. & p. p. Blotted; p. pr. & vb. n.
   Blotting.] [Cf. Dan. plette. See 3d Blot.]
   [1913 Webster]
   1. To spot, stain, or bespatter, as with ink.
      [1913 Webster]

            The brief was writ and blotted all with gore.
                                                  --Gascoigne.
      [1913 Webster]

   2. To impair; to damage; to mar; to soil.
      [1913 Webster]

            It blots thy beauty, as frosts do bite the meads.
                                                  --Shak.
      [1913 Webster]

   3. To stain with infamy; to disgrace.
      [1913 Webster]

            Blot not thy innocence with guiltless blood. --Rowe.
      [1913 Webster]

   4. To obliterate, as writing with ink; to cancel; to efface;
      -- generally with out; as, to blot out a word or a
      sentence. Often figuratively; as, to blot out offenses.
      [1913 Webster]

            One act like this blots out a thousand crimes.
                                                  --Dryden.
      [1913 Webster]

   5. To obscure; to eclipse; to shadow.
      [1913 Webster]

            He sung how earth blots the moon's gilded wane.
                                                  --Cowley.
      [1913 Webster]

   6. To dry, as writing, with blotting paper.
      [1913 Webster]

   Syn: To obliterate; expunge; erase; efface; cancel; tarnish;
        disgrace; blur; sully; smear; smutch.
        [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Blot \Blot\, n. [Cf. Dan. blot bare, naked, Sw. blott, d. bloot,
   G. bloss, and perh. E. bloat.]
   1. (Backgammon)
      (a) An exposure of a single man to be taken up.
      (b) A single man left on a point, exposed to be taken up.
          [1913 Webster]

                He is too great a master of his art to make a
                blot which may be so easily hit.  --Dryden.
          [1913 Webster]

   2. A weak point; a failing; an exposed point or mark.
      [1913 Webster]

WordNet (r) 3.0 (2006):

blot
    n 1: a blemish made by dirt; "he had a smudge on his cheek"
         [syn: smudge, spot, blot, daub, smear, smirch,
         slur]
    2: an act that brings discredit to the person who does it; "he
       made a huge blot on his copybook" [syn: blot, smear,
       smirch, spot, stain]
    v 1: dry (ink) with blotting paper
    2: make a spot or mark onto; "The wine spotted the tablecloth"
       [syn: spot, fleck, blob, blot]

Moby Thesaurus II by Grady Ward, 1.0:

229 Moby Thesaurus words for "blot":
   absorb, adsorb, air-dry, anhydrate, annihilate, aspersion,
   assimilate, attaint, baboon, badge of infamy, bag, bake,
   bar sinister, baton, bedarken, bend sinister, besmirch, bespatter,
   bespeckle, bespot, bestain, black, black eye, black mark, blacken,
   blackwash, blemish, bloodstain, blot out, blot up, blotch,
   blotting, blotting out, blow upon, blur, brand, broad arrow, brush,
   burn, cancel, cancellation, censure, champain, charcoal, chemisorb,
   chemosorb, conceal, cork, cover up, cross out, cure, dab, darken,
   daub, deface, defame, defect, defile, dehumidify, dehydrate, dele,
   delete, deletion, demolish, denigrate, desiccate, destroy, digest,
   dim, dinge, disapprove, discolor, disfigure, disfigurement,
   disparage, disparagement, dog, drain, drink, drink in, drink up,
   dry, dysphemize, ebonize, eclipse, efface, effacement, engross,
   erase, erasure, err, evaporate, expose, expose to infamy,
   expunction, expunge, exsiccate, eyesore, filter in, fire, flaw,
   fleck, flick, flyspeck, freckle, fright, gargoyle, gibbet, hag,
   hang in effigy, harridan, hide, imbibe, imputation, infiltrate,
   ink, insolate, kiln, look a fright, look a mess, look bad,
   look like hell, look something terrible, macula, maculate,
   maculation, macule, mar, mark, mark of Cain, melanize, mess,
   monster, monstrosity, mummify, murk, nigrify, no beauty,
   obliterate, obliteration, obscure, odium, offend, offend the eye,
   onus, osmose, oversmoke, parch, patch, percolate in, pillory,
   pillorying, point champain, raze, reflection, reprimand, reproach,
   rub, rub out, rule out, scar, scarecrow, scorch, scratch,
   scratch out, scrubbing, sear, seep in, shade, shadow, shrivel,
   sight, sin, slur, slurp up, smear, smirch, smoke, smouch, smudge,
   smut, smutch, soak in, soak up, soil, soilage, soilure, soot, sorb,
   spatter, speck, speckle, splash, splatter, splotch, spoil, sponge,
   sponge out, spot, stain, stigma, stigmatism, stigmatization,
   stigmatize, strike out, sully, sun, sun-dry, swab, swill up, taint,
   take in, take up, tarnish, teratism, torrefy, towel, transgress,
   uglify, ugly duckling, vilify, washing out, weazen, wipe, wipe out,
   wiping out, witch, wither, wizen



Easton's 1897 Bible Dictionary:

Blot
   a stain or reproach (Job 31:7; Prov. 9:7). To blot out sin is to
   forgive it (Ps. 51:1, 9; Isa. 44:22; Acts 3:19). Christ's
   blotting out the handwriting of ordinances was his fulfilling
   the law in our behalf (Col. 2:14).