The Collaborative International Dictionary of English v.0.48:

Stain \Stain\, v. i.
   To give or receive a stain; to grow dim.
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The Collaborative International Dictionary of English v.0.48:

Stain \Stain\ (st[=a]n), v. t. [imp. & p. p. Stained
   (st[=a]nd); p. pr. & vb. n. Staining.] [Abbrev. fr.
   distain.]
   1. To discolor by the application of foreign matter; to make
      foul; to spot; as, to stain the hand with dye; armor
      stained with blood.
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   2. To color, as wood, glass, paper, cloth, or the like, by
      processes affecting, chemically or otherwise, the material
      itself; to tinge with a color or colors combining with, or
      penetrating, the substance; to dye; as, to stain wood with
      acids, colored washes, paint rubbed in, etc.; to stain
      glass.
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   3. To spot with guilt or infamy; to bring reproach on; to
      blot; to soil; to tarnish.
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            Of honor void,
            Of innocence, of faith, of purity,
            Our wonted ornaments now soiled and stained.
                                                  --Milton.
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   4. To cause to seem inferior or soiled by comparison.
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            She stains the ripest virgins of her age. --Beau. &
                                                  Fl.
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            That did all other beasts in beauty stain.
                                                  --Spenser.
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   Stained glass, glass colored or stained by certain metallic
      pigments fused into its substance, -- often used for
      making ornamental windows.
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   Syn: To paint; dye; blot; soil; sully; discolor; disgrace;
        taint.

   Usage: Paint, Stain, Dye. These denote three different
          processes; the first mechanical, the other two,
          chiefly chemical. To paint a thing is to spread a coat
          of coloring matter over it; to stain or dye a thing is
          to impart color to its substance. To stain is said
          chiefly of solids, as wood, glass, paper; to dye, of
          fibrous substances, textile fabrics, etc.; the one,
          commonly, a simple process, as applying a wash; the
          other more complex, as fixing colors by mordants.
          [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Stain \Stain\, n.
   1. A discoloration by foreign matter; a spot; as, a stain on
      a garment or cloth. --Shak.
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   2. A natural spot of a color different from the gound.
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            Swift trouts, diversified with crimson stains.
                                                  --Pope.
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   3. Taint of guilt; tarnish; disgrace; reproach.
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            Nor death itself can wholly wash their stains.
                                                  --Dryden.
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            Our opinion . . . is, I trust, without any blemish
            or stain of heresy.                   --Hooker.
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   4. Cause of reproach; shame. --Sir P. Sidney.
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   5. A tincture; a tinge. [R.]
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            You have some stain of soldier in you. --Shak.
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   Syn: Blot; spot; taint; pollution; blemish; tarnish; color;
        disgrace; infamy; shame.
        [1913 Webster]

WordNet (r) 3.0 (2006):

stain
    n 1: a soiled or discolored appearance; "the wine left a dark
         stain" [syn: stain, discoloration, discolouration]
    2: (microscopy) a dye or other coloring material that is used in
       microscopy to make structures visible
    3: the state of being covered with unclean things [syn: dirt,
       filth, grime, soil, stain, grease, grunge]
    4: a symbol of disgrace or infamy; "And the Lord set a mark upon
       Cain"--Genesis [syn: mark, stigma, brand, stain]
    5: 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: color with a liquid dye or tint; "Stain this table a
         beautiful walnut color"; "people knew how to stain glass a
         beautiful blue in the middle ages"
    2: produce or leave stains; "Red wine stains the table cloth"
    3: make dirty or spotty, as by exposure to air; also used
       metaphorically; "The silver was tarnished by the long
       exposure to the air"; "Her reputation was sullied after the
       affair with a married man" [syn: tarnish, stain,
       maculate, sully, defile]
    4: color for microscopic study; "The laboratory worker dyed the
       specimen"