A reagent or dye used to stain microscope specimens so as to make some structures visible.
A discoloured spot or area.
Any of a number of non-standard tinctures used in modern heraldry.
A blemish on one's character or reputation.
A substance used to soak into a surface and colour it.
To cause to seem inferior or soiled by comparison.
To coat a surface with a stain
To treat (a microscopic specimen) with a dye, especially one that dyes specific features
To taint or tarnish someone's character or reputation
To discolour.
To become stained; to take a stain.