- Noun. A discoloured spot or area.
- Noun. A blemish on one's character or reputation.
- Noun. A substance used to soak into a surface and colour it.
- Noun. A reagent or dye used to stain microscope specimens so as to make some structures visible.
- Verb. To discolour something.
- Verb. To taint or tarnish someone's character or reputation.
- Verb. To coat a surface with a stain.
- Verb. To treat a microscope specimen with a dye.