什么是 stain?To discolor, soil, or spot.To bring into disrepute; taint or tarnish.To color (glass, for example) with a coat of penetrating liquid dye or tint.To treat (specimens for the microscope) with a reagent or dye that makes visible certain structures without affecting others.To produce or receive discolorations.A discolored or soiled spot or smudge.A blemish on one's moral character or reputation.A liquid substance applied especially to wood that penetrates the surface and imparts a rich color.A reagent or dye used for staining microscopic specimens.