staining
n. uncountable B2 Upper Intermediate US //ˈsteɪnɪŋ// UK //stˈeɪnɪŋ// stain·ing
n. the marks or colors left on a surface by something like dirt, ink, or chemicals. It can also mean the process of adding color to wood or fabric.
n. the presence of discoloured marks on a surface or the process of applying a pigment to a material. Often refers to accidental damage or intentional decorative treatment.
The old carpet shows heavy staining from years of use.
The wood required deep staining to match the dark mahogany of the existing furniture in the library.
Microscopic analysis revealed significant staining on the specimen, suggesting that the chemical reaction had progressed further than the researchers initially anticipated.