Merriam-Webster's Collegiate® Dictionary, 11th Edition
BLEACH
I. verb see: black Date: before 12th century transitive verb to remove color or stains from,
2. to make whiter or lighter especially by physical or chemical removal of color , to remove, make dull, or sanitize as if by removing color , intransitive verb to grow white or lose color, of coral ; to expel symbiotic zooxanthellae exposing a white skeleton, bleachable adjective
II. noun
Date: 1887
the act or process of bleaching, a preparation used in bleaching, the degree of whiteness obtained by bleaching