the world > matter > colour > named colours > white or whiteness > whitening > [noun] > bleaching > bleaching by exposure (3)
In specific senses. Exposure of some substance to the sun's rays, as for the purpose of drying, bleaching, or maturing.
The action or process of laying out cloth or textile fibres, esp. flax or hemp, on grass to bleach in the sunlight. Cf. grass, v. 5a. Now historical.
bleaching by exposure on the grass.