stain

• Noun

  1. A discolored spot or area caused by spillage or other contact with certain fluids or substances.
  2. A blemish on one's character or reputation.
  3. A substance used to soak into a surface and colour it.
  4. A reagent or dye used to stain microscope specimens so as to make some structures visible.
  5. One of a number of non-standard tinctures used chiefly in post-medieval heraldry, especially tenné, murrey, or sanguine.

• Verb