bluing
  靛青漂白粉
  Blue, v. t. [imp. & p. p. Blued p. pr. & vb. n. Bluing.] To make blue; to dye of a blue color; to make blue by heating, as metals, etc.
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  Blu·ing n.
  1. The act of rendering blue; as, the bluing of steel.
  2. Something, as indigo or other preparations, used to give a bluish tint, especially to white clothing when being washed.
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  bluing
       n 1: used to whiten laundry or hair or give it a bluish tinge
            [syn: blueing, blue]
       2: a process that makes something blue (or bluish) [syn: blueing]