Used as a verb it means to bleach the hair and remove current color.
When used as a noun it refers to the chemical composition designed to remove color from the hair. Bleach is sometimes referred to as a pre-lightening or decolorizing treatment.
Daily Hair Tip
There are different types of conditioners including pre-shampoo, rinse-out, leave-in and deep conditioning. Olive oil and other volume enhancing products may help strip hair color. When in doubt, ask your stylist.