1 [countable] a mark that is difficult to remove, especially one made by a liquid such as blood, coffee, or ink
stubborn stains (=ones that are very difficult to remove)
2 [uncountable and countable]TIC a special liquid that you use to change the colour of something, especially wood [↪ dye]
3 something that damages the good opinion that people have about someone

Related topics:
There was a dark red stain on the carpet.