bleaching

Concise Oxford English Dictionary © 2008 Oxford University Press:
bleach/bliːtʃ/

▶verb

• 1 make white or much lighter by a chemical process or by exposure to sunlight.

• 2 clean or sterilize with bleach.

▶noun a chemical used for bleaching and also to sterilize drains, sinks, etc.

– origin OE blǣcan (v.), blǣce (n.), from blǣc ‘pale’, of Gmc origin; rel. to bleak1.