Pronunciation: (stān),[key] —n. 1. a discoloration produced by foreign matter having penetrated into or chemically reacted with a material; a spot not easily removed.
2. a natural spot or patch of color different from that of the basic color, as on the body of an animal.
3. a cause of reproach; stigma; blemish: a stain on one's reputation. 4. coloration produced by a dye that penetrates a substance, as wood.
5. a dye made into a solution for coloring woods, textiles, etc.
6. a reagent or dye used in treating a specimen for microscopic examination.
—v.t. 1. to discolor with spots or streaks of foreign matter.
2. to bring reproach or dishonor upon; blemish.
3. to sully with guilt or infamy; corrupt.
4. to color or dye (wood, cloth, etc.) by any of various processes that change or react with the substance chemically.
5. to color with something that penetrates the substance.
6. to treat (a microscopic specimen) with some reagent or dye in order to color the whole or parts and so give distinctness, contrast of tissues, etc.
—v.i. 1. to produce a stain.
2. to become stained; take a stain: This fabric stains easily.