n.
1.a soiled or discolored appearance
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
4.a symbol of disgrace or infamy
5.an act that brings discredit to the person who does it stain v.
1.color with a liquid dye or tint
2.produce or leave stains
3.make dirty or spotty, as by exposure to air
4.color for microscopic study