n.
Function: noun
Date: 1557
1 a : a soiled or discolored spot b : a natural spot of color contrasting with the ground
2 : a taint of guilt : STIGMA
3 : a preparation (as of dye or pigment) used in staining: as a : a dye or pigment capable of penetrating the pores of wood b : a dye or mixture of dyes used in microscopy to make visible minute and transparent structures, to differentiate tissue elements, or to produce specific chemical reactions
– stain · proof \ - ˌ prüf \ adjective