A discoloration or spot on a surface, typically one that is difficult to remove. The red wine left a stubborn stain on the white carpet.
A dye or pigment used to color materials, especially in biological research to highlight structures in microscopic specimens. The scientist applied a stain to the slide to better observe the cell structures under the microscope.
A mark of disgrace or infamy; a blemish on one's reputation. The scandal left a permanent stain on the politician's career.
A translucent pigmented solution applied to wood, concrete, or similar materials to colour and highlight the surface. We applied a dark walnut stain to the deck to enhance the grain.