noun.
The art or process of freeing textile fibers and fabrics, and various other substances (such as materials for paper, ivory, wax, oils), from their natural color, and rendering them white, or nearly so.
the GNU version of the Collaborative International Dictionary of English
noun.
The act or process of whitening, by removing color or stains; esp. the process of whitening fabrics by chemical agents.
noun.
a powder for bleaching, consisting of chloride of lime, or some other chemical or chemicals.